LABORATORY APPARATUS, PROCEDURES Flashcards
why does laboratory safety matters
Safe working protects:
• You
• Other lab workers
• Cleaners
• Visitors
• Your work
how to do risk assessment
• Determine hazards and evaluate risks
• Use all relevant available data
• Determine controls needed to minimize those risks
• Document the assessment
• Use those control measures
8 control measures
- Use a less risky substance
- Use a safer form of that substance (eg solution instead of powder)
- Totally enclose the process (eg a glove-box)
- Partially enclose the process (eg with a fume cupboard)
- Ensure good general ventilation
- Safe systems of work
- Reduce exposure times, increase distance, reduce volumes
- Personal protective equipment (as a last resort for primary protection)
protecting yourself in the lab (4)
• Wear the clothing and protective wear identified in your risk assessment
• Laboratory coats must be kept fastened
• Don’t wear sandals or open shoes
• Long hair must be tied back
protecting yourself in the lab using hand gloves (4)
• There are many different types of protective glove
• Use the correct ones for the job you will be doing
• Remember that you need to select chemical protection gloves
according to the materials and/or substances with which you will
be working
• Remove your gloves before using instruments, telephone, and leaving the laboratory
enumerate laboratory hygiene (5)
• Never eat, drink or smoke in a laboratory
• Never apply cosmetics
• Never touch your face, mouth or eyes
• Never suck pens or chew pencils
• Always wash your hands before you leave and especially before eating
What are the general hazards in a laboratory? (9)
• Fire
• Breakage of glassware
• Sharps
• Spillages
• Pressure equipment & gas cylinders
• Extremes of heat & cold
• Chemical hazards
• Biological hazards
• Radiation
laboratory safety: avoiding fires (4)
• Flammable substances
• Use minimum quantity
• Store in special storage cabinet
• Use temperature-controlled heating sources (eg water-bath rather than hot- plate or Bunsen burner)
laboratory safety: fire safety (3)
• Make sure that you know
what to do:
• If you have a fire
• If you hear a fire alarm
laboratory safety: glassware (4)
• Use correct techniques for the insertion of tubing onto glassware
• Never use glassware under pressure or vacuum unless it is designed for the job and suitably shielded
• Dispose of chipped or broken glassware – it is a risk to you and others
• Always dispose of broken glass in a glass bin or sharps bin and not in a general waste bin
laboratory safety: spillages (3)
• Clear up spillage promptly
• You will already have determined how to do this as part of your risk assessment
• Dispose of any hazardous material as toxic waste
Messy workers are usually poor Messy workers are usually poor
workers!!
laboratory safety: cyrogenics (4)
• Liquid gasses are extremely cold and can cause burns
• Liquid gases evaporate and many can cause asphyxiation
• If you need to take cryogens in a lift, there are special procedures to follow – speak to your supervisor or a senior member of technical staff
• You must have special training to use them
laboratory safety: equipment (2)
• Always do a visual check on electrical equipment before
use, looking for obvious wear or defects
• NEVER use defective equipment
laboratory safety: general tidiness (4)
• Keep your workplace tidy
• Clear up waste, deal with washing up and put things away as you finish with them
• Make sure everything is safe before you leave things unattended
• A tidy laboratory avoids accidents to everyone
laboratory safety: laboratory equipment (2)
• Never use any laboratory equipment unless you are trained & have been authorised to do so
• As well as injuring yourself you may cause very costly damage
laboratory safety: protecting yourself
• If you have an allergy to lab materials or suffer from a medical
condition which may affect you in the laboratory (eg asthma or epilepsy), ensure that your professor knows
when in doubt, what are you going to do
ASK
• Do not carry out a new or unfamiliar procedure until you have been fully trained & understand the precautions necessary for safe
working
• DO NOT GUESS!!!!
what do MSDS means
Material Safety Data Sheet
RACE stands for
R - Rescue
A - Alarm
C - Contain
E - Extinguish
PASS ( Fire Extinguisher)
P - Pull the pin
A - Aim to the base of the fire
S - Squeeze the lever
S - sweep the noodle side to side
acid to water, correct or not?
yes, Always add acid to water, not water to acid. Otherwise, the acid can splatter and splash up. When you mix strong acids and water, it makes a difference whether you add acid to water or water to acid. Always add acid to water and not the other way around.
a ventilated enclosure used to trap and exhaust vapors, gases, and nanoparticles
Fumehood
3 types of gloves
Latex Gloves
Surgical Gloves
Nitrile Gloves
Why many seconds are you going to wash your hands after the exposure in the lab
20 seconds
how to handle waste
15 - 30 seconds put 10% bleaching with tissue
5 mins alcohol with tissue
means a container either especially designed for the disposal of hypodermic needles or a plastic container suitable for this purpose, or for plate glass may be a rigid reusable container or cardboard box
Puncture Proof
in using electricity in laboratory. what type of pronged plug we use
3 pronged plug
used in disposal of infectious waste
Yellow Plastic Bag
used to dispose chemicals
Black Plastic Bag
2 types of units of measurement
Metric System
International System (SI unit)
Based on decimal system; a system of divisions and multiples of tens
Metric System
standard measurement of length
m
standard measurement of weight
g
standard measurement of volume
L
Standardized system based on seven base units
International System (SI units)
SI system: measurement: length, unit name? abbreviation?
Meter (m)
SI system: measurement: mass, unit name? abbreviation?
kilogram (kg)
SI system: measurement: time, unit name? abbreviation?
second (s)
SI system: measurement: amount of substance, unit name? abbreviation?
Mole (mol)
SI system: measurement: electrical current, unit name? abbreviation?
Ampere (A)
SI system: measurement: temperature, unit name? abbreviation?
kelvin (k)
SI system: measurement: luminous Intensity, unit name? abbreviation?
Candela (cd)
SI system: prefix: Tera, symbol? factor?
T (10 to the power of 12)
SI system: prefix: Giga, symbol? factor?
G (10 to the power of 9)
SI system: prefix: Mega, symbol? factor?
M (10 to the power of 6)
SI system: prefix: Kilo, symbol? factor?
k ( 1 to the power of 3)
SI system: prefix: Hecto, symbol? factor?
h (10 to the power of 2)
SI system: prefix: Deka, symbol? factor?
da (10 to then power of 1)
SI system: prefix: deci, symbol? factor?
d (10 to the power of -1)
SI system: prefix: centi, symbol? factor?
c ( 10 to the power of -2)
SI system: prefix: milli, symbol? factor?
m ( 10 to the power of -3)
SI system: prefix: micro, symbol? factor?
u ( 10 to the power of -6)
SI system: prefix: nano, symbol? factor?
n ( 10 to the power of -9)
SI system: prefix: pico, symbol? factor?
p ( 10 to the power of -12 )
SI system: prefix: femto, symbol? factor?
f ( 10 to the power of -15 )
SI system: prefix: Atto, symbol? factor?
a ( 10 to the power of -18 )
the standard unit for measurement of length is
meter
the standard unit for measurement of mass is
kilogram
the standard unit for measurement of volume is in
liters
the standard unit for measurement of amount of substance
mole
Basic laboratory principles includes: (5)
• Patient preparation
• Proper collection
• Proper specimen handling and processing
• Hiring, Training and Management
• Quality assurance program (Reagent, glasswares and plastic wares, equipment, personnel and outcome/result)
Any substance employed to induce chemical reaction; a substance that is used to test for the presence of another substance by causing a chemical reaction with it
Reagents
You have to note about reagents
• Chemical reagents comes with varying grade of purity
• MSDS
• Essential in giving ACCURATE results
• Spectrograde, nanograde, HPLC grade, – highest purity
• ACS, USP-NF, NBS, OSRM, CAP, NCCLS,
reagents: Techniques on use and storage
• Optimal storage condition
• Can be used directly or needed reconstitution
• Safety hazard
• MSDS
5 types of reagent
- Reagent grade (RG) or Analytical grade (AR)
- Chemical pure grade (CP)
- Standard
- Less pure grade
- USP and NF
2 types of standard reagent
Primary Standard
Secondary Standard
2 types of less grade reagent
Purified Grade
Technical Grade
These chemicals met specifications designed to
permit use in quantitative and qualitative analysis; controls
Reagent grade (RG) or Analytical grade (AR)
Purity is usually delivered by measurement of melting point or boiling point
Chemical pure grade (CP)
highly purified chemicals which maybe weighed out directly for the
preparation of solutions of selected concentration or for the standardization of solutions of unknown strength
Primary Standard
solutions whose concentration cannot be determined directly
from the weight of solute an volume of the solution
Secondary standard
in general these chemicals should not be used in clinical determination
Purified grade
generally used in manufacturing
Technical grade
Represents other grades of purity. While they are adequate for human consumption, they may not be pure enough for specific chemical determinations
USP and NF
3 types of reagent water
TYPE I REAGENT WATER
TYPE II REAGENT WATER
TYPE III REAGENT WATER
Use for procedure that use maximum water purity
TYPE I REAGENT WATER
TYPE I REAGENT WATER is use for
• Preparation of standard solution;
• Ultramicrochemical analyses
• Measurement of nano or subnanogram concentration
• Tissue or cell culture methods, electrophoresis,toxicology,
Use for most of clinical laboratory determination.,
hematology,immunology,microbio
TYPE II REAGENT WATER
For most of the qualitative measurement
TYPE III REAGENT WATER
TYPE III REAGENT WATER is use for
Urinalysis, parasitology, histology, washing glasswares
distilled water is being redistilled with alkaline permanganate solution that oxidizes the nitrogenous matter present – Conductivity water
DISTILLATION
(abbreviated “ddH2O”, “Bidest. water” or “DDW”) is prepared by double distillation of water. It was the standard for highly purified laboratory water for biochemistry and trace analysis until combination methods of purification became widespread
Double distillation -Double-distilled water
also known as demineralized water (DI water, DIW or de- ionized water) water that has had its mineral ions removed, such as cations from sodium, calcium, iron, copper and anions such as chloride and
bromide.
DEIONIZATION
a physical process which uses specially-manufactured
ion exchange resins which bind to and filter out the mineral salts from water. Because the majority of water impurities are dissolved salts, It produces a high purity water that is generally similar to distilled water, and this process is quick and without scale buildup. However, it does not significantly remove uncharged organic molecules, viruses or bacteria, except by incidental trapping in the resin. Specially made strong base anion resins can remove Gram-negative bacteria
Deionization
It can be done continuously and inexpensively using electrodeionization. It does not remove the hydroxide or hydronium ions from water. These are the products of the self-ionization of water to equilibrium and therefore are impossible to remove.
Deionization
water: other processes are also used to purify water,
including:
• reverse osmosis
• carbon filtration
• microporous filtration
• ultrafiltration
• ultraviolet oxidation
• electrodialysis.
• Processes rendering water potable but not necessarily closer
to being pure H2O / hydroxide + hydronium ions include use
of dilute sodium hypochlorite, mixed-oxidants (electro-
catalyzed H2O + NaCl), and iodine
1 meter to inches is equal to
39.37 inches
1 in to cm is equals to
2.54 cm
1 kg to lbs is equal to
2.2 lbs
the process of configuring an instrument to provide a result for a sample within an acceptable range
Calibration
Calibration: (2)
• Class S (weights 1-500mg)
• Adjustments and realignment
2 types of top loading balances
Single pan top balances
Electronic balances
principle of weighing by substitution; weighs up to 10kg
Single pan top balances
highly sensitive; 130kg capacity; principle is based on a strict linear relationship between compensation current and force produced by the load placed on the pan
Electronic balances
the measurement of the quantity of matter in a liquid state
Volume
used to measure volume
Clinical laboratory glasswares
an amorphous (non-crystalline) solid material
Glasswares
typically brittle and optically transparent
Glasses
5 types of glassware
a. High thermal resistant
b. High silica glass
c. High alkali resistant glass
d. Standard flint glass
e. Low actinic glass
a type of glass with the main glass-forming
constituents silica and boron oxide; are known for having very low coefficients of thermal expansion (~3 × 10−6 /°C at 20°C),
making them resistant to thermal shock.
High thermal resistant / Borosilicate glasswares
not used for strong alkali; Such glass is less subject to thermal stress and is commonly used for the construction of reagent bottles
Low alkali content and free from magnesia-lime-zinc element
glassware for ashing and ignition teschnique
Kimax, pyrex (515),vycor (900)
- Comparable to fused quarts in its thermal endurance, chemical
stability, electrical characteristics - Radiation resistant and good optical quality
- Used in precision analytical work and can also used for optical
reflectors and mirrors - Corex - cuvette
High silica Glass – 96%
- Not as resistant as pyrex to heat therefore need to heat and cool
carefully - Used to handle strong alkali solution
High alkali resistant glass
- A high thermal with red color added as an integral part
- Used for light sensitive reagents
Standard Flint glass
- Composed of mixture of the oxides of silicon, calcium and sodium
- Poor resistance to high temperature
- Pipette, regular tubes and glasswares
Low actinic glass / soda Lime glass
A long and straightsided \ cylindrical piece of glassware with calibration; Used to measure where less
accuracy is needed
Graduated cylinder
Long cylindrical graduated pipettes with stopcock (glass or
Rubber); Used for titration
Biuret
Are frequently used for preparation of standard solutions; Measures liquid volume accurately
Volumetric flasks
Wide straight sided cylindrical vessels that are available in many
sizes; Used generally for mixing and for
reagent preparation
Beaker
are often used for preparing reagents and titration purposes
Erlenmeyer Flask
comes in different sizes depending on their intended
use; Chemical reaction medium
Test tubes
Cleaning laboratory glasswares (2)
• Rinse and immediately placed in a weak detergent
• Chromic acid with sodium or potassium dichromate, concentrated
sulfuric acid and distilled water
• Used the principle of dry heat
• 160 degrees for 1-2 hours
Hot air sterilizer
Another type of volumetric glassware used extensively in the laboratory; Calibration is according to deliver or transfer a specific volume from one vessel to another
Pipettes
calibrated to deliver the amount of fluid designated on the pipette; this volume will flow out of the pipette by gravity; Calibration is usually performed by measuring the amount of water delivered by the pipette.
To deliver (TD)
3 types of pipette
• According to manner of calibration
• According to graduation
• Specialized pipettes
Example of specialized pipettes
• Micropipettes
• Unopette
• Capillary pipette
• Automatic pipettor
calibrated by introducing exact amount of volume or weight of mercury; it contains exact amount however does not deliver
the exact volume
To contain (TC)
similar to TD except that the volume is obtained when the last drop is being blown out. An etched or frosted ring indicated this calibration
To blow out pipette
exact volume is calibrated to fill the volume between 2
calibratess points on the pipette
Calibrated between the marks
According to calibration: (4)
- To deliver (TD)
- To contain (TC)
- To blow out pipette
- Calibrated between the marks
has a cylindrical bulb located midway the mouthpiece and the tip
Volumetric or transfer pipette
similar to volumetric pipette but has a larger buld closer to delivery tip and it has an etched ring that indicates that it is a blow out; Used to measure viscous substance ex. Blood and serum
Ostwald –Folin pipette
plain narrow tube draw out to a tip and graduated uniformly along its length; calibrated to deliver fractional quantity specifically reagents
Measuring or graduated pipette
2 types of measuring or graduated pipette
a. Mohr
b. Serologic Pipette
According to graduations: (2)
- Volumetric or transfer pipette
- Measuring or graduated pipette
Calibrated to contain or to wash out the pipettes; 1 lambda = 1uL =
0.001mL
Micropipettes
4 example of micropipettes
a. Kirk transfer pipette
b. Self filling transfer pipette
c. Lang levy pipette
d. Overflow pipette
1 lambda = uL? mL?
1uL
0.001mL
TC OR TD: Kirk transfer pipette
TC
TC OR TD: Self filling transfer pipette
TC
TC OR TD: Lang levy pipette
TD
TC OR TD: Overflow pipette
TC
A special disposable micropipette used in the hematology laboratory; It is self filling pipette accompanied by polyethylene
reagent reservoir
Unopette
fitted in a plastic holder and fill automatically with blood by means of capillary action
capillary pipette
Inexpensive, disposable micropipette; It is filled up to the calibrated line by capillary action and measured liquid is delivered by
positive pressure as with a medicine dropper
Capillary pipette
Allows rapid, repetitive measurement and delivery of
predetermined volumes of reagents or specimens; 0.5-500 uL
Automated pipettor
Pipetting technique (6)
• Check pipette before using – wet, chipped or broken
• Hold properly between thumb and forefinger
• Wipe the pipette with a soft tissue or lint free cloth
• Hold the pipette vertically
• Do not mouth pipette
• Read the meniscus
Read the meniscus (3)
• Bottom of the meniscus
• Upper meniscus
• Eye level
separates substances with different densities by centrifugal
force (Substance is separated into precipitate and supernatant); Speed is usually given in revolutions per minute; More satisfactory than filtration; The faster the speed the longer the radius, the better quality of the filtrate
Centrifugation
Parts of Centrifugation:
• Tachometer
• Loader
• Knobs
Parts of Centrifugation function: calibrator
Tachometer
Parts of Centrifugation function: balance sets of test tube placers
Loader
Parts of Centrifugation function: break, speed regulator, timer
Knobs
Types of Centrifuge (6)
Table top model
Floor model
Refrigerated centrifuge
Ultracentrifuge
Cytocentrifuge,
Serofuge.
two traditional centrifuge used in the laboratory:
• Horizontal head centrifuge / swinging bucket
• Fixed angle head centrifuge ex. Microhematocrit centrifuge
The number of revolutions per minute and the centrifugal force
generated are expressed as r; 600rpm – 7300rcf
Centrifuge speed – rpm
Factors that affect centrifugation: (7)
• To balance the centrifuge
• Cover the specimen being processed
• Used proper centrifuge tubes
• Always checked for the rubber cushion
• Cover the centrifuge while rotating
• Do not try to stop the centrifuge with your bare hands
• Centrifuge should be checked, cleaned and lubricated regularly
Usually accomplished by gravtiy, pressure or suction
Filtration
filter paper folded into conical shape or 60 degree cone
Gravity filtration
4 types of filtration equipment
Gravity filtration
Funnel
Porcelain Buchner funnel
Porous Glass filters
refers to the substance being dissolved which may be a solid,
liquid or gas
SOLUTE
refers to the substance in which solute is being dissolved,
which in most cases are liquid
SOLVENT
refers to the weight or volume of the solute present in a specific amount of the solvent or a solution
concentration of solutions
3 types of concentration of solution
• Percentage
• Molarity
• Normality
Refers to the parts of solute per 100 parts of solvent; The amount of solute in a solution can be measured as a percentage of
the total volume of solution
Percent solution
Formula for percent solution
% = solute/100
refers to the number of grams of solute per 100mL solution:
Weight in volume percent solution (W/V)
Formula: Weight in volume percent solution (W/V)
grams of solute = desired (% solution) x volume desired (total)
/100
used when both solute and solvent are liquid. It refers to the amount of solute in mL in 100 mL of solvent
Volume in volume percent solution (V/V)
Formula: Volume in volume percent solution (V/V)
mLof solute = desired (% solution) x volume desired (total) / 100
it refers to grams of solute per 100 grams of solution
Weight in weight percent solution (W/W)
Formula: Weight in weight percent solution (W/W)
mL of Conc. = mL/ gm solute X %W/V desired X Final vol(mL)/ 100
defined as a solution containing one gram molecular weight ( one mole of the solute in one liter solution) of the substance per liter of the solution
molar solution of a substance
equal to the number of moles of solute per liter of solution
(solvent)
Molarity
obtained by adding the atomic weights of the component elements in their proper proportions in the formula
molecular weight of one compound