Safety, Lab Equipment, Units and Dilutions Flashcards
What are the three basic units of measurement for length, weight and volume in the SI system?
Length = meter (m) Mass = gram (g) Volume = litre (L)
What do you do to get a deci (d) from 1 unit?
Times by 10. A deci (d) is 1/10 of 1 unit.
How many centimeters (cm) in a meter(m)?
Times by 100. A centi (c) is 1/100 of 1 unit. (Or move decimal to the right two places).
What are the seven units of the SI system?
Meter for length Kilogram for mas Mole for concentration Second for time Ampere for electric current Kelvin for temperature Candela for light intensity
What is the formula for molarity?
Molarity or moles/liter =
(gram/gram molecular weight) / 1L
What are the two parts to a dilution?
- The sample that is to be diluted.
2. The diluent used to perform the dilution, e.g. water.
What are the two parts to a solution?
- A solute, which is the part being placed into the solution.
- The solvent - the liquid which the solute is being diluted into.
What is a general description of a dilution?
Weaker solution is made from a more concentrated solution.
What is the equation for dilution ratio?
Dilution Ratio = Vs / (Vs + Vd)
where
Vs = volume of substance being diluted and
Vd = volume of diluent
How is a dilution ratio typically expressed?
It is expressed in a ratio of lowest terms. Expressed as the ratio of 1 to a number. The numerator needs to be 1.
What is the formula for concentrations of dilutions?
Original Concentration x Dilution Ratio = New Concentration
What terms or units and concentrations be described as?
Concentrations can be in %, g/L (weight per volume), M (molarity), or N (normality).
What are beakers typically used for in a med lab?
Name some characteristics
General reagent prep Allows a lot of evaporation Markings are approximate Can heat Cannot use to measure with any degree of accuracy
What are graduated cylinders used for?
Accuracy?
Measure volume of liquids.
Not as accurate as volumetric flask.
What are Erlenmeyer flasks used for?
General preparation and mixing of reagents
Good for boiling or heating (less evaporation)
Not used for critical measurements. Accuracy is similar to beaker (lines are approximate).
What are Volumetric Flasks used for?
Measures exact volume if meniscus is at the line.
Most accurate.
Used if measurement is critical.
What are funnels used for?
Aids in getting chemicals or liquids in flasks or storage bottles.
Can use with filter paper.
What are burets and clamps used for?
Glass tube (buret) with a valve near one end that deliveries known volumes of liquid. The clamp holds the buret in place. Flow of liquid is controlled by the valve. Used for analytical chemistry.
What a scoopulas used for?
Used to transfer dry chemicals usually to a weigh boat for weighing
What is a mortar and pestle used for?
Used to grind up dry chemicals, pills, or crystals to be dissolved
What is a transfer pipette used for?
Pasteur pipettes or transfer pipettes used frequently in labs
Can be made of either plastic or glass
Used to transfer liquid from one container or tube to another
What’s a bulb or pi pump used for?
Used to aspirate (draw up) liquid into macro pipettes.
What are storage bottles used for and made of?
Can be used to store chemicals or to discard particular chemicals that are volatile.
Made of glass or plastic.
What are four types of glass materials used in the lab?
Flint glass
Borosilicate
Quartz glass
Low actinic glass
What are characteristics of flint glass?
inexpensive
low resistance to heat and chemicals
What are characteristics of borosilicate glass?
Nonreactive with most chemicals.
High thermal resistance.
Eg. Pyrex and Kimax.
What are characteristics of quartz glass?
Expensive
High silica content
Has excellent light transmission without distortion (good for cuvettes)
What are characteristics of low actinic glass?
Amber/Brown in colour
Helps protect light sensitive chemicals
What are types of plasticware used?
Polyethylene – can be clear, cheap, very common
Polypropylene - milky or opaque, heat resistant, can be autoclaved
Polystyrene – clear, rigid
All are lightweight, impact resistant, corrosion resistant.
Teflon – white, stopcocks in burets
What are transfer pipettes used for?
Frequently used in labs to transfer liquid from one container to the other.
What are conical centrifuge tubes used for?
Used to spin fluids (microbiology) in a centrifuge – for example knee fluids or abdominal fluids
What are stir bars or magnetic stirrers with retriever used for?
Stirring chemicals.
What can be used to heat and evaporate liquid to hydrate it out?
Evaporating dish.
What is a MacBick bottle used for?
Used in Microbiology lab to sterilize media. Cap on bottle is designed that it can be autoclavable, steam goes in..
What is a fleaker?
Combination flask and beaker
Not for critical measurements
Has a lid
What are methods to clean glassware?
May have to autoclave or clean with bleach
Detergent – scrub (we use sparkleen)
Tap water
Distilled water rinse x 3
Dry in oven or leave on rack to air dry
What safety precautions need to be taken with glass?
Precautions: Inspect for chips and cracks If breakage clean with dustpan and broom Use borosilicate when heating When inserting glass tubing: Lubricate Wrap glass in towel so it doesn’t crack Hold 1” to 2” from end Gently twist into stopper
What are mixers, blenders used for?
Usually used to mix media or microorganisms in saline to make a suspension
Precautions:
Greatest danger is aerosols
So operate inside BSC, wait one min before opening lids, if open use a towel soaked in disinfectant and disinfect surfaces after used.
What are some precautions for microscopes?
Inspect electrical cords regularly
Disinfect regularly
Slides not fixed are considered infectious
Set up station ergonomically
What are some precautions for automated equipment?
Only fix if you are authorized Store reagents correctly Visually inspect tubing and connections Use safety shield in front of sampling probe Wear gloves Disinfect lines Verify waste line discharges meet regulations Avoid over-filling sample cups Disinfect prior to servicing
What are the hazards and precautions for cryostats?
Hazards: Physical (temperature, cuts) Biological Precautions: Keep cover closed when cutting Wear gloves and mask (can inhale dust) Routinely decontaminate parts Routine = 70 - 100% Ethanol Suspected TB = tuberculosis disinfectant Creutzfeldt-Jakob Disease = sodium hydroxide Defrost weekly For STAT tissues (i.e. need results ASAP, and microtome inside so lock handle when not in use).
What are some precautions for electrophoresis apparatus?
Inspect electrical components regularly Verify integrity of tank Locate away from high traffic areas Display proper signs “High Voltage” (Used for eletrophoresis during molecular .....)
What are some precautions for a chemical fume hood?
Evaluate prior to use for adequate face velocity Hoods should be left on at all times Have sash at appropriate height Keep sash clean NEVER store chemicals in hood Avoid sudden movements Should have an audible alarm
True or False. A chemical fume hood and a biological safety cabinet is essential the same thing.
False. A chemical fume hood is used for chemicals and a Biological Safety Cabinet is used for biologicals.
In what colour binder is the safe work practices in for all labs?
In all of the labs the Safe Work Practices binder is YELLOW.
What is a centrifuge?
Rotates at a high speed around a central axis separating components of different densities contained in a liquid.
Heavier substances go towards the bottom of the tube due to gravity.
What is the formula for RCF (Relative Centrifugal Force)?
RCF = K x r x n^2, where K = 1.118 x 10^-5, r is radius from center in cm n is RPM
Why do we need to calculate RCF?
To figure what speed and times the BD Vacutainer and Blood Collection tubes should be spun at.
Example, BD Vacutainer spun at 1000 to 1300 RCF for 10 min in a swing bucket centrifuge.
