Laboratory Operations Flashcards
recognition granted by non-governmental agency to institutions that meet certain standards; voluntary
accreditation
examples: AABB, CAP, JCAHO, NAACLS
recognition granted by non-governmental agency to individuals who meet education requirements and demonstrate entry-level competency by passing exam; voluntary
certification
examples: AAB, ASCP, AMT
permission granted by state to individuals/organizations to engage in certain professions/businesses; mandatory; illegal to practice/operate in that state without license
licensure
examples: licensure of lab personnel is required in CA, FL, HI, LA, MT, NV, NY, MD, RI, TN, WV
technical standards and accreditation of blood banks
AABB (formerly American Association of Blood Banks)
standards on all aspects of lab practice developed through voluntary consensus
CLSI (Clinical Laboratory & Standards Institute), formerly NCCLS
standards to facilitate international exchange of goods and services; developed through voluntary worldwide consensus
ISO (international organization for standards)
defines standards for quality management in medical labs
ISO 15189
writes regulations for and enforces CLIA ‘88
Centers for Medicare and Medicaid Services (CMS)
interprets and implements federal regulations related to health care
Department of Health and Human Resources (HHS)
oversees CDC, CMS, FDA, SAMSHA
HHS
regulates packaging, labeling, and transportation of biological products
Department of Transportation (DOT)
regulates disposal of toxic chemicals and biohazardous wastes
Environmental Protection Agency (EPA)
regulates market entry of instruments/reagents and production of donor blood and components; licenses blood banks
Food and Drug Administration (FDA)
licenses labs that use radionucleotides
Nuclear Regulatory Commission (NRC)
regulates employee safety in the workplace
OSHA
certifies laboratories to conduct forensic drug testing for federal agencies
Substance Abuse and Mental Health Services Administration (SAMHSA)
requires employers to inform employees about hazardous substances in workplace and educate them in safe handling
Hazard Communication Standard (OSHA 1983) “Right-to-Know Law”
regulates all lab testing (except research) performed on humans in U.S. Requirements for personnel and quality assurance determined by test complexity; administered by CMS
Clinical Laboratory Improvement Amendments of 1988 “CLIA ‘88”
requires chemical hygiene plan to minimize personnel exposure to hazardous chemicals in the lab
Occupation Exposure to Hazardous Chemicals in Laboratories (OSHA 1990) “Laboratory Standard”
mandates work practices and procedures to minimize worker exposure to bloodborne pathogens
Bloodborne Pathogens Standard (OSHA 1991)
requires monitoring of formaldehyde exposure
Formaldehyde standard (OSHA 1992)
regulates use and disclosure of protected health information (PHI)
Health Insurance Portability and Accountability Act of 1996 “HIPAA”
tests cleared by the FDA for home use, negligible likelihood of erroneous results, or no reasonable risk of harm to patient if performed incorrectly
waived
QC of waived tests
none required other than to follow manufacturers guidelines
proficiency testing of waived tests
not required
testing personnel minimum qualifications of waived tests
none specified
certain microscopic exams performed by provider during patient’s visit (e.g., direct wet mount, KOH prep, urine sediment)
Provider-Performed Microscopy (PPM)
QC of PPM
required when controls are available; otherwise reference materials (e.g., photomicrographs) fulfill requirement
PT of PPM
PT not specifically required, but labs must verify accuracy of testing twice annually; can be through PT, split sampling, or blind testing
testing personnel minimum requirements for PPM
physician, midlevel provider, or dentist
score <= 12 on 7 criteria
(knowledge, training/experience, reagent/material prep, characteristics of operational steps, calibration/quality control/proficiency testing materials, test system troubleshooting, interpretation/judgment)
moderate complexity
QC for moderate complexity testing
2 levels of external controls each day of testing
PT for moderate complexity testing
required
testing personnel minimum qualifications for moderate complexity testing
high school diploma or equivalent and training for testing provided
score >12 on 7 criteria
(knowledge, training/experience, reagent/material prep, characteristics of operational steps, calibration/quality control/proficiency testing materials, test system troubleshooting, interpretation/judgment)
high complexity
QC for high complexity testing
2 levels of external controls each day of testing
PT for high complexity testing
required
testing personnel minimum qualifications for high complexity testing
associate degree in medical laboratory technology or equivalent
standard to protect health-care workers from occupational exposure to bloodborne pathogens
Bloodborne pathogens standard of 1991
primary requirements of the Bloodborne Pathogens Standard
- exposure control plan
- universal precautions
- engineering controls
- work practice controls
- personal protective clothing and equipment
- housekeeping
- training
- medical surveillance
- hep b vaccine
- hazard communications
- sharps injury log
blood
potentially infectious
tissues
potentially infectious
semen
potentially infectious
vaginal secretions
potentially infectious
CSF
potentially infectious
synovial fluid
potentially infectious
pleural fluid
potentially infectious
peritoneal fluid
potentially infectious
pericardial fluid
potentially infectious
amniotic fluid
potentially infectious
saliva in dental procedures
potentially infectious
feces
usually not infectious unless visibly bloody
nasal secretions
usually not infectious unless visibly bloody
sputum
usually not infectious unless visibly bloody
sweat
usually not infectious unless visibly bloody
tears
usually not infectious unless visibly bloody
urine
usually not infectious unless visibly bloody
vomitus
usually not infectious unless visibly bloody
packaging of biologics for shipping
- primary container - test tube, vial, etc containing etiologic agent; must be securely closed, watertight, surrounded by absorbent material and placed in secondary container
- secondary container - must be watertight, sealed, and placed in approved mailing container
- mailing container - must be made of fiberboard
- labeling - biohazard label required on primary and mailing containers
- training - employees must be trained and retrained every 2-3 years or when regulations change
also known as “Right-to-Know Law”; “HAZCOM”
Hazard Communication Standard (HCS)
standard to inform employees about chemical hazards in workplace and protective measures
Hazard Communication Standard (HCS)
primary requirements of HCS
- written hazard communication plan
- inventory of hazardous chemicals on site
- hazard labeling
- material safety data sheets (MSDS) for each chemical readily accessible to employees on each shift
- training on initial assignment and when new hazard introduced
also known as “Laboratory Standard”; “Chemical Hygiene Standard”
Occupational Exposures to Hazardous Chemicals in Laboratories Standard
standard to limit employee exposure to hazardous chemicals to levels at or below permissible exposure levels (PELs)
Occupational Exposures to Hazardous Chemicals in Laboratories Standard
primary requirements for the Occupational Exposures to Hazardous Chemicals in Laboratories Standard
1.
visible destruction of human tissue on contact; can cause injury on inhalation or contact
corrosives
e.g., glacial acetic acid, hydrochloric acid, sodium hydroxide
interfere with metabolic processes when ingested, inhaled, or absorbed through skin
toxic substances
e.g. cyanides, sulfides
capable of causing cancer
carcinogens
e.g., benzidine, formaldehyde
induce genetic mutations; cause defects in embryo
mutagens and teratogens
e.g., benzene, lead, mercury, radioactive material, toluene
capable of causing fire
ignitables
e.g., acetone, alcohols, ether, xylene
lowest temperature that produces ignitable vapor
flashpoint
capable of causing an explosion
reactives
e.g., ether, perchloric acid, picric acid, sodium azide
forms explosive peroxides on exposure to air or light; store in explosion-proof refrigerator
ether
may react explosively with organic compounds; separate from other acids
perchloric acid
shock sensitive when dehydrated; more powerful than TNT
picric acid
solutions can form explosive lead or copper azides in drains
sodium azide
Describe the safety diamond.
Blue diamond (left) - health 0 = no hazard 1 = can cause sig. irritation 2 = can cause temp. incapacitation or residual injury 3 = can cause serious or permanent injury 4 = can be lethal
Red diamond (top) - flammability 0 = will not burn 1 = flashpoint above 200*F (must be preheated before ignition can occur) 2 = flashpoint below 200*F (must be heated or high ambient temp. to burn) 3 = flashpoint below 100*F (can be ignited under almost all ambient temps.) 4 = flashpoint below 73*F (will vaporize and readily burn at normal temperatures)
Yellow diamond (right) - instability 0 = stable 1 = normally stable; high temps. make unstable 2 = violent chemical change at high temps. or pressures 3 = may explode at high temps. or shock (shock + heat may detonate) 4 = may explode at normal temps. and pressures (may detonate)
White diamond (bottom) - special hazards ALK = alkaline ACID = acidic COR = corrosive OX = oxidizing Radioactive symbol = radioactive W with line through it = reacts violently or explosively with water W with line through it and OX = reacts violently or explosively with water and oxidizing
storage of acids
(1) store below counter level or in acid cabinets
(2) separate from flammable and combustible material, bases and active metals (e.g., sodium, potassium, magnesium)
(3) separate organic acids from inorganic acids
(4) separate oxidizing acids from organic acids
storage of bases
(1) separate from acids
(2) store inorganic hydroxides in polyethylene containers
storage of flammables
(1) limit amount in work area
(2) store in approved safety cans or cabinets
(3) separate from oxidizing acids and oxidizers
storage of oxidizers
(1) separate from reducing agents (e.g., zinc, alkaline metals, formic acid), flammable, and combustible materials
storage of water-reactive chemicals
(1) keep away from water
(2) store in a dry, cool place
examples of organic acids
formic, glacial acetic, citric
examples of inorganic acids
hydrochloric, nitric, sulfuric
examples of oxidizing acids
chromic, nitric, perchloric, sulfuric
examples of bases
ammonium hydroxide, potassium hydroxide, sodium hydroxide
examples of flammables
acetone, alcohols, xylene
examples of oxidizers
nitric acid, perchloric acid, sulfuric acid, acetic acid, potassium chloride, hydrogen peroxide
examples of water-reactive chemicals
sodium, potassium
Class A fires
combustible material: cloth, wood, paper
extinguishers to use: pressurized water (A) , dry chemical (ABC)
comments: do not use water on electrical fires or burning liquids
Class B fires
combustible material: flammable or combustible liquids
extinguishers to use: dry chemical (ABC), CO2 (BC)
Class C fires
combustible material: electrical equipment
extinguishers to use: dry chemical (ABC), CO2 (BC)
comments: never use water; dry chemical may damage electrical equipment; CO2 leaves no residue; good choice for analyzers, computers
Class D fires
combustible material: combustible metals
extinguishers to use: leave to professional firefighters
What additive/anticoagulant is in a lavendar topped tube?
EDTA
What is the mode of action of EDTA?
prevents clotting by chelating calcium
Which colored tube should be at least 1/2 full?
lavendar
Which anticoagulant/additive prevents platelets from clumping?
EDTA
What is the benefit of using EDTA as an anticoagulant/additive in tubes for CBCs and differentials?
EDTA causes minimal morphologic changes to WBCs
What additive/anticoagulant is in a light green tube?
heparin
What is the mode of action of heparin?
prevents clotting by neutralizing thrombin
What types of tests can be done using tubes with EDTA?
CBC, diff, sed rate
What is the best anticoagulant, additive for prevention of hemolysis?
heparin
Why can’t you use heparin tubes for differentials?
because it creates a blue background
What additive/anticoagulant is in a light blue tube?
sodium citrate
What is the mode of action of sodium citrate?
prevents clotting by binding calcium
What type of tests can be done using tubes with heparin?
many chemistries, osmotic fragility, plasma hemoglobin, blood gases
What type of tests can be done using tubes with sodium citrate?
most coagulation tests
Which additive/anticoagulant preserves labile clotting factors?
sodium citrate
Why should sodium citrate tubes be full (of blood)?
so that a 9:1 blood-to-anticoagulant ratio can be obtained; if NOT, then coag results will be falsely increased
What happens to coagulation results if sodium citrate tubes are not full (of blood)?
the results will be falsely increased
What type of additive/anticoagulant is in a gray topped tube?
sodium fluoride
What is the mode of action of sodium fluoride?
inhibits glycolysis (not an anticoagulant)
Which tube would you use if you wanted to preserve glucose for 24 hours?
gray-top (sodium fluoride)
What is added to a sodium fluoride tube if anticoagulation is needed?
potassium oxalate
What is the mode of action of oxalate?
binds calcium
What is the recommended order for drawing evacuated tubes and filling tubes from a syringe?
1) blood culture [yellow (SPS)] or blood culture bottles
2) coagulation (citrate) [light blue]
3) serum (with/without clot activator; with/without gel) [red, gold, speckled]
4) heparin (with/without gel) [green]
5) EDTA [lavendar, pink, white]
6) glycolytic inhibitor (Na fluoride/K oxalate) [gray]
Why should blood culture tubes/bottles be drawn first?
avoids bacterial contamination from needle that has pierced other stoppers
Why should citrate (light blue) tubes be drawn before other anticoagulant and clot activator tubes?
avoids contamination with additives that can affect coag results
Why should serum (red, gold, speckled) tubes be drawn before green tubes?
avoids contamination with sodium heparin (increased sodium) or lithium heparin (increased lithium)
Why should serum (red, gold, speckled) tubes be drawn before lavendar tubes?
avoids contamination from K2EDTA (decreased calcium, magnesium; increased potassium)
Why should serum (red, gold, speckled) tubes be drawn before gray tubes?
avoids contamination with sodium fluoride/potassium oxalate (decreased calcium; increased sodium; increased potassium; interference with some enzyme assays)
What results would be affected by drawing a green tube before a serum tube?
sodium (increased)
lithium (increased)
What results would be affected by drawing a lavender tube before a serum tube?
calcium (decreased)
magnesium (decreased)
potassium (increased)
What results would be affected by drawing a gray tube before a serum tube?
calcium (decreased)
sodium (increased)
potassium (increased)
interference with some enzyme assays
Why should green tubes be drawn before lavender tubes?
avoids contamination from K2EDTA (decreased calcium, magnesium; increased potassium)
Why should green tubes be drawn before gray tubes?
avoids contamination with sodium fluoride/potassium oxalate (decreased calcium, increased sodium, increased potassium)
What results would be affected by drawing a lavender tube before a green tube?
calcium (decreased)
magnesium (decreased)
potassium (increased)
What results would be affected by drawing a gray tube before a green tube?
calcium (decreased)
sodium (increased)
potassium (increased)
Why should lavender tubes be drawn before gray tubes?
avoids contamination with oxalate, which alters cellular morphology
What would be altered if gray tubes were drawn before lavender tube?
cellular morphology would be altered due to the oxalate
What is the recommended order of filling microcollection tubes from capillary punctures?
1) blood gases - minimizes air exposure
2) EDTA - minimizes clumping of platelets
3) other additive tubes - minimizes clotting
4) serum tubes - clotting is not a concern
What should you do if a phlebotomy patient has an IV?
1) use opposite arm or perform fingerstick
2) have nurse turn off IV for 2 minutes, apply tourniquet below IV site, use different vein if possible; document location of IV and venipuncture, type of fluid
What should you do if a phlebotomy patient has a fistula?
draw from opposite arm
What should you do if a phlebotomy patient has indwelling lines and catheters, heparin locks, cannulas?
1) usually not drawn by lab
2) first 5 mL drawn should be discarded
3) lab may draw below heparin lock if nothing is being infused
What should you do if a phlebotomy patient has sclerosed veins?
select another site
What should you do if a phlebotomy patient has a hematoma?
draw below hematoma
What should you do if a phlebotomy patient has streptokinase/tissue plasminogen activator (TPA)?
1) minimize venipunctures
2) hold pressure until bleeding has stopped
What should you do if a phlebotomy patient has edema?
select another site
What should you do if a phlebotomy patient has scars, burns, or tattoos?
select another site
What should you do if a phlebotomy patient has had a mastectomy?
draw from opposite arm
What should you do if a phlebotomy patient refuses a blood draw?
1) try to persuade
2) if unsuccessful, notify nurse
What could happen if you draw from a patient that has refused to have his/her blood drawn?
could lead to charges of assault and battery
What should you do if a phlebotomy patient is unidentified?
ask nurse to ID before drawing
What are some examples of tests that require the patient to be fasting?
fasting blood glucose triglycerides lipid panel gastrin insulin
How long must a patient fast if a test requires fasting?
at least 8 hours (nothing to eat or drink, except water)
What are some examples of tests that require the sample to be chilled (slurry of crushed iced and water)?
ACTH acetone ammonia gastrin glucagon lactic acid pyruvate PTH renin
What are some examples of tests that require the sample to be warmed?
cold agglutinins
cryoglobulins
What are some examples of tests that require the sample to be protected from light (wrap in aluminum foil)?
bilirubin carotene erythrocyte protoporphyrin vitamin A vitamin B12
What are some examples of tests that require chain of custody?
any test used as evidence in legal proceedings; e.g., blood alcohol, drug screens, DNA analysis
What are possible effects of misidentifying a patient during phlebotomy?
treatment errors
possibility of transfusion fatality
What are possible effects of drawing a patient at an incorrect time?
treatment errors if samples for certain tests aren’t drawn at appropriate times, e.g., therapeutic drug monitoring, analytes that exhibit diurnal variation, analytes that are affected by recent eating/drinking
What are possible effects of drawing blood from an edematous site?
dilution of sample with tissue fluid
What are possible effects of the patient fist pumping during venipuncture?
increased potassium increased lactic acid increased calcium increased phosphorus decreased pH
What are possible effects of leaving a tourniquet on longer than 1 minute?
increased potassium
increased total protein
increased lactic acid
What are possible effects of IV fluid contamination when performing phlebotomy?
increased glucose, electrolytes (depending on IV)
What are possible effects of using expired collection tubes during phlebotomy?
decreased vacuum, failure to obtain specimen
What are possible effects of using an incorrect anticoagulant or contamination from incorrect order of draw?
K2EDTA before serum or heparin tube: decreased calcium, decreased magnesium, increased potassium
contamination of citrate tube with clot activator: erroneous coag results
What are possible effects of failing to hold the bottom of a tube lower than the top during blood collection?
carryover from one tube to another
possible additive contamination
What are possible effects of short draws during phlebotomy?
incorrect blood: anticoagulant ratio affects some results, e.g., coag tests
What are possible effects of inadequate mixing of an anticoagulant tube?
micro-clots, fibrin, platelet clumping can lead to erroneous results
What are possible effects of hemolysis from alcohol contamination, “milking” site of capillary puncture, probing with needle, vigorous shaking of tubes, and exposure of samples to extremes of temperature?
increased potassium
increased magnesium
increased LD
increased iron
How long/fast should you centrifuge most tubes?
1000-1300 RCF for 10-15 minutes
How long/fast should you centrifuge citrate tubes?
1500 RCF for 15 minutes to produce platelet-poor plasma
Why should tubes remain capped during centrifugation?
avoid loss of CO2, change of pH, evaporation, or aerosol formation
Why should you not re-spin primary tubes?
can cause hemolysis
What should you do if recentrifuging a primary tube is necessary?
transfer serum/plasma to another tube
Why should you not re-spin serum separator tubes?
serum in contact with RBCs under gel can be expressed and increase potassium
How long can separated serum/plasma be kept?
RT for 8 hours
2-8C for 48 hours
for longer storage: -20C
Can you freeze whole blood in tubes?
NO
Explain relative centrifugal force (RCF).
Force acting on sample being centrifuged. Gravities (g). Function of rpm and radius.
RCF = 1.12 x 10^-5 x r x rpm^2
Explain rpm.
revolutions per minute
speed of centrifugation
determined by tachometer
Explain radius (r).
distance in cm from center of rotation to bottom of tube when rotating
centrifuge in which tubes are in horizontal position when rotating; produces a tightly packed, flat sediment surface; recommended for serum separator tubes
horizontal-head centrifuge (swinging-bucket)
centrifuge in which tubes are at fixed angle (25-40*) when rotating; capable of higher speeds; produces a slanted sediment that isn’t tightly packed; decantation is not recommended
angle-head centrifuge
high-speed centrifuge capable of 100,000 rpm; recommended to reduce heat
ultra centrifuge
missing or inadequate label
REJECT
collected at wrong time
REJECT
collected in wrong tube
REJECT
insufficient specimen
REJECT
inadequate volume of blood in anticoagulant tube
REJECT
exposure to temperature extremes
REJECT
prolonged transit
REJECT
clots in CBC tube
REJECT
hemolysis
REJECT (depends on test ordered)
lipemia
REJECT (depends on test ordered)
What type of glass has high resistance to thermal shock and chemical attack?
borosilicate glass (Kimax, Pyrex)
What type of glass has heavy walls to minimize breakage?
borosilicate glass
What type of glass is used for most beakers, flasks, and pipets?
borosilicate glass
What type of glass causes minimal contamination of liquids by elements in glass?
borosilicate glass
What type of glass can be heated and autoclaved?
borosilicate glass
What type of glass is 6 times stronger than borosilicate?
aluminosilicate glass (Corex)
What type of glass is better able to resist clouding due to alkali and scratching?
aluminosilicate glass
What type of glass is used for highly alkaline solutions?
boron free glass
What type of glass is alkali resistant?
boron free glass
What type of glass has poor heat resistance?
boron free glass
What type of glass has heat, chemical, and electrical tolerance?
high silica glass
What type of glass has excellent optical properties?
high silica glass
What type of glass is used for high-precision analytic work, optical reflectors, and mirrors?
high silica glass
What type of glass is soda-lime glass containing oxides of sodium, silicon, and calcium?
flint glass
What type of glass is least expensive but has poor resistance to high temps and sudden changes of temp?
flint glass
What type of glass has only fair resistance to chemicals?
flint glass
What type of glass can release alkali and affect some determinations?
flint glass
What type of glass is used for some disposable glassware?
flint glass
What type of glass is amber or red?
low actinic glass
What type of glass is used to decrease exposure to light (e.g., bilirubin standards)?
low actinic glass
What type of plastics are relatively inert chemically?
polypropylene and polyethylene
What type of plastic is resistant to most acids, alkalis, and salts?
polypropylene
What type of plastic can be autoclaved?
polypropylene
What type of plastic is used for pipet tips and test tubes?
polypropylene
What type of plastic is resistant to most acids (except concentrate H2SO4), alkalis, and salts?
polyethylene
What type of plastic is used for test tubes, bottles, disposable transfer pipets, and test tube racks?
polyethylene
What types of plastic cannot be autoclaved?
polyethylene and polystyrene
What type of plastic is stronger than polypropylene and has better temp tolerance, but chemical resistance not as good?
polycarbonate
What types of plastics are clear?
polycarbonate and polystyrene
What type of plastic is resistant to shattering?
polycarbonate
What type of plastic is used for centrifuge tubes and graduated cylinders?
polycarbonate
What type of plastic is rigid and clear?
polystyrene
What type of plastic will crack and splinter?
polystyrene
What type of plastic is used for test tubes and graduated tubes?
polystyrene
What type of plastic is soft and flexible, but porous?
polyvinyl chloride
What type of plastic is frequently used as tubing?
polyvinyl chloride
What type of plastic is extremely inert?
teflon
What type of plastic has excellent temp tolerance and chemical resistance?
teflon
What type of plastic is used for stir bars, stopcocks, and tubing?
teflon
Glassware inscription: A
Class A; meets high standards for accuracy
Glassware inscription: 20*C
temp of calibration; temp glassware and solutions should be for maximum accuracy
Glassware inscription: TC
to contain; vessel calibrated to hold specified volume (e.g., volumetric flask)
Glassware inscription: TD
to deliver; vessel calibrated to deliver specified volume (e.g., graduated cylinder)
wide-mouthed, straight-sided jar with pouring spout; not accurate enough for critical measurements
beaker
sloping sides; graduated markings; used to hold liquids, mix solutions, measure noncritical volumes
Erlenmeyer flask
spherical base with long cylindrical neck; single calibration mark; only for noncritical measurements
Florence flask
pear shaped; long neck with single calibration mark; manufactured to strict standards; glassware and solutions should be at RT; used to prepare standards and reagents; shouldn’t be used to store solutions
volumetric flask
upright, straight-sided tube with flared base; used for noncritical measurements; most are TD; shouldn’t be used to measure <5 mL or <10% of capacity; use graduate closest in size to volume to be measured
graduated cylinder (graduates)
transfer pipet; single calibration mark; calibrated to accurately deliver fixed volume of nonviscous samples and standards; touch off last drop against wall of receiving vessel
volumetric pipet
transfer pipet; similar to volumetric pipet but bulb closer to tip; etched ring means blowout; used for accurate measurement of viscous fluids, e.g., whole blood; not widely used
Ostwald-Folin pipet
graduated or measuring pipet; graduation marks down to tip; etched ring means blowout; can be used for serial dilutions and measuring reagents; not accurate enough for measuring samples or standards
serological pipet
graduated or measuring pipet; doesn’t have graduation marks all the way to the tip or frosted band near upper end; delivery is made “point to point;” not widely used
Mohr pipet
disposable pipet for volumes ranging from 1-1000 uL; single calibration mark; filled by capillary action; TC; must be rinsed out with diluent to deliver exact amount; small pipetting bulb is used
micropipet
What type of mechanical micropipet does the following description describe?
“uses suction to aspirate and dispense sample through polypropylene tip; 1- or2-stop; with 2-stop, button is depressed to 2nd stop to “blow out;” tips can only be used once; seals require periodic lubrication”
air displacement micropipet
What type of mechanical micropipet does the following description describe?
“uses a glass capillary tip fitted with Teflon-tipped plunger; no carryover; tips are reusable; plunger setting must be checked and Teflon tip replaced periodically”
positive displacement micropipet
When should you verify accuracy and precision for mechanical micropipets?
on receipt, after service/repair, and on regular schedule
What is the most accurate method for calibrating mechanical micropipets?
gravimetric method (weight of distilled water delivered)
What is a secondary method for calibrating mechanical micropipets (after gravimetric method)?
spectrophotometric (absorbance of potassium dichromate or p-nitrophenol delivered)
What type of chemical grade does the following description describe?
“very high purity; meets specifications of American Chemical Society”
analytic reagent grade
What chemical grade is recommended for qualitative and quantitative analysis?
analytic reagent grade
What type of chemical grade does the following description describe?
“spectrograde, nanograde, or HPLC grade”
ultra pure
What chemical grade is used for gas chromatography, HPLC, fluorometry, and trace metal determinations?
ultra pure
What type of chemical grade does the following description describe?
“limits of impurities not specified; may be acceptable for some lab applications when higher purity chemicals aren’t available”
chemically pure
What type of chemical grade does the following description describe?
“for industrial use; not of sufficient purity to sue as analytic reagents”
practical, technical, or commercial grade
What type of chemical grade does the following description describe?
“meet specifications of U.S. Pharmacopeia or National Formulary; not injurious to health; not necessarily of sufficient purity to use as analytic reagents”
USP or NF grade
What labeling requirements are not required by CAP?
date received, date opened
least expensive objective; partially corrects for chromatic and spherical abberations
achromatic objective
controls angle and amount of light sent to objective
aperture diaphragm
microscope with 2 oculars
binocular microscope
used to eliminate yellow color emitted by tungsten
blue filter
microscope that uses transmitted light and lenses; objects appear dark against white background; used for most routine clinical work
Brightfield microscope
microscope with 2 lens systems - objectives and oculars
compound microscope
focuses light on specimen
condenser
distance throughout which all parts of specimen are in focus simultaneously
depth of focus
limits area of illumination to image field
field diaphragm
area of specimen that can be seen
field of view
used to help objective gather light from a wide numerical aperture; provides high resolution; type B (high viscosity) is commonly used
immersion oil
method of focusing and centering light path and spreading light uniformly; ensures optimum contrast and resolution
Kohler illumination
magnification of ocular x magnification of objective
total magnification
What is the highest magnification achievable with a Brightfield microscope?
1,000x
mathematical expression of light admitted by lens
numerical aperture (NA)
The higher the NA, the greater the ____________.
resolution
lenses attached to revolving nosepiece; most commonly used are low power (10x), high power (40x), and oil immersion (50x or 100x)
objectives
eye piece; usually 10x
ocular
object in center of field at 1 magnification will be in center of field at other magnifications
parcentric
object remains in focus from 1 magnification to another
parfocal
more expensive objective that corrects for curvature of field; results in flat field with uniform focus
planachromatic objective
ability to reveal fine detail and distinguish between 2 close points
resolution
light control knob
rheostat
Light intensity shouldn’t be regulated by ____________ or _________.
condenser or diaphragms
type of bulb used for brightfield microscopy
Tungsten-halogen bulb
image seen through microscope; upside down and reversed
virtual image
distance between slide and objective
working distance
Working distance ___________ with higher magnification objectives.
decreases
brightfield microscope with special condenser; objects appear white against a black background
darkfield microscope
What microscope can be used for the identification of live Treponema pallidum and other microorganisms?
darkfield microscope
brightfield microscope with 2 special filters; fluorescent dyes absorb light of 1 wavelength and emit light of longer wavelength; objects appear green, yellow, or orange against a black background
fluorescent microscope
What microscope can be used in direct and indirect fluorescent antibody stains in microbiology and immunology?
fluorescent microscope
brightfield microscope with special slit aperture below condenser, polarizer, and special amplitude filter (modulator) in back of each objective; gives 3-D effect to unstained specimens
interference contrast
What microscope can be used for wet mounts?
interference contrast
brightfield microscope with phase condenser and phase objectives; subtle differences in refractive index converted to clear-cut variations of light intensity and contrast; good for living cells, unstained specimens
phase contrast
What microscope can be used for manual platelet counts, urine sediments (good for hyaline casts)
phase contrast
brightfield microscope with 2 crossing filters - polarizing filter below condenser, analyzer between objective and eyepiece; objects that can refract light (birefringent) appear white against black background
polarizing microscope
What microscope can be used for the identification of crystals in urine and synovial fluid and for confirmation of fat or oval fat bodies in urine sediment?
polarizing microscope
beam of electrons passes through specimen, focused onto fluorescent screen or photographic plate; magnification >100,000x
transmission electron microscope
What type of microscope can be used to see viruses and cells (organelles)?
transmission electron microscope
beam of electrons strikes surface of specimen, focused onto photographic film or cathode ray tube; 3-D image; magnification >1,000x
scanning electron microscope
What type of microscope can be used to see viruses and cells (surface)?
scanning electron microscope
information science; science of processing data for storage, retrieval, and use
informatics
use of computers and information systems to process and communicate information generated in clinical lab
laboratory informatics
computerized medical record; American Recovery and Reinvestment Act of 2009 (ARRA) calls for EMRs for all patients by 2014 to help reduce cost and increase efficiency of health-care delivery
electronic medical record (EMR)
physical parts of computer
hardware
executes software instructions
central processing unit (CPU)
working memory used for temporary storage of programs and data; content is lost each time computer is turned off
random access memory (RAM)
part of memory that is permanently protected from being modified, erased, or written over; not affected by power loss; used for boot-level and other system instructions
read-only memory (ROM)
magnetic-coated metal plate inside CPU for storing data
hard drive
device that reads data stored on magnetic or optical disk and writes data onto disk for storage
disk drive
CDs, DVDs; store data
optical disk
input/output and information storage components
peripheral drives
devices that deliver data to computer, e.g., keyboards, barcode readers, computer links (interfaces)
input devices
devices by which computer delivers data, e.g., printers, monitors
output devices
input/output device that allows computers to communicate over telephone lines
modem
programs that tell computer what to do
software
program that controls basic functions of computer, e.g., Microsoft Windows
operating system software
programs designed to meet specific needs of users, e.g., word processing
application software
application program that allows for manipulation of text; used to write letters, reports, etc.
word processor
application program to manipulate numbers and perform mathematical calculations; used to prepare financial statements, budgets, etc.
spreadsheet
application program to organize, store, sort, and retrieve data (words and numbers)
database
program that provides access to internet, e.g., Microsoft Internet Explorer
browser
system of hardware, software, connections, and communication protocols to handle all informational needs of lab, from intake of requests to delivery of results; can provide patient information, test information, collection lists, work lists, test results, financial functions, productivity/workload monitoring, quality management, and interface with other computer systems
Laboratory information system (LIS)
information system to handle all informational needs of hospital, both clinical and administrative
Hospital information system (HIS)
hardware and software that allow for electronic communication between 2 computer systems, even if they use different programming languages; the LIS is typically interfaced with HIS and automated analyzers
interface
interface that transmits electronic information in 1 direction, e.g., a point-of-care analyzer downloads test results to LIS
unidirectional interface
interface that transmits electronic information in 2 directions, e.g., the LIS downloads orders from the HIS and uploads results to the HIS
bidirectional interface
interface between an analyzer and LIS; can apply rules to automate processes, e.g., autoverification (automatic release of results without tech review when certain criteria are met)
middleware
documentation that LIS functions as expected; required by regulatory agencies
system validation
computer network that connects computers in close geographic proximity (e.g., building, campus)
local area network (LAN)
computer network that connects computers over large geographic area (e..g, multisite health-care facility, internet)
wide area network (WAN)
global system of interconnected computer networks
internet
computer network within an organization; access is usually restricted to employees
intranet
extension of a private network onto the internet where it can be accessed by authorized clients, suppliers, etc.
extranet
common set of signals and rules that network uses for communication
protocol
one of the 1st protocols developed for connecting computers
ethernet
originally developed as transfer protocol for internet; adapted for transmission in LANs
transmission control protocol/internet protocol (TCP/IP)
standardized message protocol that facilitates exchange of medical data among computer systems
Health Level 7 standard (HL7)
process by which lab ensures quality results by closely monitoring preanalytical, analytical, and postanalytical stages of testing
quality assessment or quality assurance (QA)
everything that precedes test performance, e.g., test ordering, patient preparation, patient ID, specimen collection, specimen transport, specimen processing
preanalytical QA
everything related to assay, e.g., test analysis, QC, reagents, calibration, preventive maintenance
analytical QA
everything that comes after test analysis, e.g., verification of calculations and reference ranges, review of results, notification of critical values, result reporting, test interpretation by physician, follow-up patient care
postanalytical QA
all of the lab’s policies, processes, procedures, and resources needed to achieve quality testing
quality system
part of analytical phase of quality assurance; process of monitoring results from control samples to verify accuracy of patient results
quality control (QC)
sample that is chemically and physically similar to unknown specimen and is tested in exactly the same manner; monitors precision of test system
control
For nonwaived quantitative tests, CLIA requires at least _______ levels of control each day test is performed. For qualitative tests, ___________ must be included in each run.
2 levels
pos & neg controls
testing control material not built into the test system; term also used for QC that extends beyond the lab, e.g., participation in proficiency testing program
external QC
electronic, internal, or procedural controls that are built into the test system
internal monitoring systems
labs may reduce frequency of testing external QC materials for certain test systems if they can demonstrate through a CMS-approved QC evaluation process that the test system is stable
equivalent QC
statistical parameters describing spread of data about mean, e.g., standard deviation, coefficient of variation, range; measurements of precision
measures of dispersion
difference tween highest and lowest values in a data set
range
sum of all observations divided by number of observations; average of all observations
mean
statistical expression of dispersion of values around the mean; requires a minimum of 20 values
standard deviation
expresses standard deviation as a percentage
coefficient of variation
The _____ the CV, the _______ the precision.
- lower
2. greater
Explain normal distribution/Gaussian bell-shaped curve.
68% of values fall within +/- 1 SD of mean
95% of values fall within +/- 2 SD of mean
99.7% of values fall within +/- 3 SD of mean
range within which control values must fall for assay to be considered valid; many labs use mean +/- 2 SD; 1 determination in 20 will fall outside +/- 2 SD
control limits
normal distribution curve lying on its side, marked with mean, +/-1, +/-2, +/-3
Levey-Jennings chart
a control result outside established limits
outlier
6 consecutive control values on same side of mean
shift
control values increasing or decreasing for 6 consecutive runs
trend