Cc lec Flashcards
studies or tests biochemical by-products and constituents; analytes such as metabolites
Clinical chemistry
part of the metabolic process that is needed to test to determine normal levels/ any abnormal levels that can indicate a disease.
Biochemical by-products
the substance measured in a test
Analyte
Two types of testing:
Qulitative
Quantitative
to detect the PRESENCE/ABSENCE of an analyte. (eg. Screening Tests for Drug Testing)
Qualitatively
to measure the CONCENTRATION of an analyte. (eg. Confirmatory Tests for Drug Testing)
Quantitatively
the fluid collected from the patient that is “NOT YET PROCESSED” (newly collected)
Specimen
the fluid collected from the same patient that is “NOW PROCESSED OR CENTRIFUGED”
Serum
involves all activities/procedures that are carried
but before the actual analysis or testing activities
PRE-ANALYTICAL TESTING
Can affect the following analytes: ▪ Lipids
▪ Calcium ▪ Enzymes ▪ Proteins ▪ Drugs
POSTURE
Best time for Collection: MORNING
▪ Pertains to the fluctuation that occurs during daytime
Diurnal rhythm
Prior to phlebotomy can affect the following analytes:
Creatinine
Protein
Creatine kinase
Platelets
Wbc
Ast
Ldh
Aldolase
Sex hormones
Exercise
Causes an increase in WBC counts, FI, FV, FVIII:c, and FXIII
Stress
indicates increase in fatty foods consumption
Chylomicrons
(Fasting) to correctly measure the EXOGENOUS source of substances
Diet
Can affect false measurements
▪ If sample still cloudy/turbid after fasting,
it indicates a disease (lipid metabolism)
▪ LIPID: 12 hrs strict fasting
▪ FBS/Glucose: 6-8 hrs o If both: 10 hrs.
▪ Over fasting for glucose: false decrease
▪ Under fasting for lipids: false increase
▪ Prolonged Fasting:
o 48 hrs: Bilirubin
o 72 hrs: Plasma glucose 💻 hypoglycemia
Cbc test
Prior to phlebotomy can affect the following analytes:
Smoking
Increases WBC and cortisol
Smoking
Increases Plasma Lactate, Urates, Triglycerides
Alcohol or ethanol consumotion
Physiologic Interference
In vivo
Peritoneal Fluid
Paracentesis
Perxardiocentensis
Pericardial fluid
Preferred specimen in urine
First morning midtsream ( routine urinalysis)
Tests that require the specimen to be placed in ice water/ cold water
Plasma renin
Acid phosphatase
Blood ammonia
SPECIMEN PROCESSING
Three Phases
Pre centrifugation
Centrifugation
Post centrfugation
Always inspect tube labels and cracks
✓ Make sure that it’s balanced
✓ Make sure that the machine is regularly calibrated
(Tachometer)
Pre centrifugation
Speed depends on the type of specimen
✓ Identify what speed first.
Centrifugation
Immediately transfer serum/plasma sample to a sterile tube
Post-centrifugation
Fundamental process in the preparation of standards, reagents, gravimetric analysis, or calibration of volumetric equipment requiring the use of analytical balances
Measurement of Mass
Requires the use of glass wares for the determination of the
volume of the liquid reagents, samples or body fluids. o Pyrex (Borosilicate)
▪ Commonly used
▪ High degree of thermal resistance
▪ Low alkali content ▪ Free from heavy metals
Measurement of Volume
Temperature-dependent reaction, test, or procedures
▪ Enzyme measurements - E.g., as a biocatalyst, it needs to be optimally reacting as to the body temp (37degC)
Control of Temperature
Performed to remove excess water or solvent in the sample o There is better test for sensitivity because of accurate
Evaporation and Specimen Concentration
Depends on the measurement of the analytical response curve. o Analytical response curve: used for the determination of
analytical sensitivity
o Analytical Sensitivity: pertains to the smallest possible
concentration of an analyte that can be measured in a test
Detection of Analytical Response
procedures or activities necessary after the actual measurement or analytical testing
POST ANALYTICAL TESTING
Software system that records, manages, and stores data for clinical laboratories
→ There is still physical documentation like logbooks, printed our results, etc.
Laboratory Information System
Specimen: depending on what type
o Blood samples: freezing at -18decC or colder Freezing: can
preserve the biochemical constituents.
o Serum or Plasma: Refrigerator (only for 72hrs) o Urine: Refrigerator (only for 24hrs)
→ Lab Reports: unclaimed results are kept for 2 years
o Transferred to the medical records after 2 yrs
Retention of Specimen and Laboratory Reports
b. Ultrapure Reagents
→ Suitable for techniques that require extremely pure chemicals
→ Molecular & Reference techniques
→ Atomic Absorption Spectrometry (AAS)
→ Enzyme immunoassay (EIA) - Molecular diagnostics MDx
→ Polymerase Chain Reaction
Ultrapore
High-performance liquid
chromatography
HPLC or chromatographic
s used to a certain acceptable purity range of
this reagent
Melting point analysis
type of organic reagent with some impurities
Practical grade
a type of organic reagent that approaches the purity level of a reagent grade type with some impurities
Chemically pure
This type of reagent is spectrally pure
Spectroscopic grade
The minimum purity level is at 99%
→ The purity level is determined by gas chromatography
Chromatographic grade
This is the ASC grade type
→ It is certified to contain impurities below certain levels established by ACS
Reagent grade
Purified by distillation process
→ Distillation process:
✓ There is heating process followed by cooling.
✓ Evaporation followed by condensation
✓ After cooling, the distilled water will be collected in a
separate vessel
Disttilled water
Water is purified by Ion Exchange Resin
→ It could either be a cation or anion or mixed type
→ Ions are removed from water
→ Removal of Ion
→ Dissolved solids and dissolved gasses are also removed
Deionized water
It utilizes pressure to force water through a semi-permeable membrane
→ Applied pressure - membrane - pure water
→ After passing through the membrane, the water will be then
purified
→ This does not remove dissolved gasses
Reverse Osmosis (RO) water
UV oxidation, sterilization, or ozone treatment
→ Used to destroy pathogens or microorganisms that can
cause bacteria or disease
→ Destroys endotoxins, pyrogens
Ultrafiltration and nano filtered water
The one that is used in the preparation of reagents
→ Used in reagent grade type (AR, Ultrapure)
→ Prepared by initial filtration, followed by reverse osmosis,
and then Deionization, and finally second filtration using 0.2
mm filter
→ 4 times to purify
Reagent grade water
For test methods requiring minimum interference
=>
→ Example: Trace Metal Analysis by Flame emission
Type I water
For analytical preparation
→ Reagent and Standard Preparation
→ Quality Control Preparation
Type II water
Warming components is necessary for analytical procedures and is accomplished by circulating water/ice baths or heating/cooling metal blocks.
→ Temperature monitoring
→ The temperature can directly affect the performance
of the test and the result of the analysis
3.
2. GLASSWARES
3.
→ Laboratory supplies consisted of some type of glass
✓ Kimax® /Pyrex® (borosilicate): most preferred
✓ Corex® (aluminosilicate)
✓ High silica
✓ Vycor® (acid or alkali resistant)
✓ Low actinic (amber colored)
✓ Flint glass (lime soda)
®: registered trademark
PLASTIC WARE
→ →
THERMOMETERS
Use of a colored liquid or mercury encased in plastic/glass
material with a bulb at one end of the graduated stem o Not anymore used in the lab or hospital setting
Liquid-in-glass
Surface thermometer: at the side or top of incubators or
heating ove
Liquid in glass
Fast reading with millisecond response time
o Usually used in the laboratory to measure room
temperature
o Someforfreezer/refrigeratortemperature(thecordis
inside, with the metal part) o 20-24degC–roomtemp
Electronic thermometer or thermistor probe
Used to determine and monitor body temperature
Digital thermometer
Asyntheticaromaticpolymer
o Clear, hard, and brittle, and as a thermoplastic
polymer it is in a solid glassy state
o One of the most widely used plastics
o Great for general sample storage and transport
and is commonly used in lab supplies like test
tubes, microplates, and petri dishes. o Disposablepetridishes
Polystyrene
Athermoplasticpolymer
o Commonly used to manufacture plastic lab
supplies like beakers, bottles, flasks, test tubes,
and many others.
o Different from polystyrene - Rugged and
Polypropylene
If high heat resistance opaque appearance
Autoclave
Used for viscous samples/fluids
o Uses mercury as a calibrating medium
o Proper use requires rinsing of the pipet with the final
solution after content are delivered into the diluent
(rinsing technique)
o Rinsed since the viscous sample might have sticked to the walls
o We use automatic pipettes now. As Hg, is a hazard.
According to Design or Calibration Marks
The separation of particles in a liquid solution based on
on exposure to air difference in their ability to pass through a membrane
→ Not used in lab today → The micromolecules are separated from the macromolecules
→ Urea is a micromolecule (removed, separated), retained in the BALANCES: blood are protein which is a macromolecule
Dialysis
