LABORATORY EQUIPMENT

Heat blocks and water baths

Common heating units within the laboratory

Thermometers

Integral part of an instrument or need to be placed in the device for temperature maintenance and monitoring

Liquid-in-glass thermometers

Uses a colored liquid, encased in plastic or glass, measuring temperatures between 20 C and 400 C

Replaced

If a liquid-in-glass thermometer has separation or bubbles in the liquid, the thermometer must be what?

NIST-certified thermometer

Liquid-in-glass thermometers should be calibrated against what?

NIST (national institute of standards and technology)

Has an SRM (standard reference material) thermometer with various calibration points for use with liquid in glass thermometers

Gallium

Has a known melting point and can also be used for thermometer verification

Thermistor

Special typpe of resistor whose electrical resistance changes a lot based on its temperature

Class A glassware

Stamped with letter A on the glassware and are preferred for laboratory applications

Class B glassware

Generally have twice the tolerance limits of class A, and are found in student laboratories where durability is needed

To contain glassware

Glassware that holds or transfers liquid that do not deliver the volume measured when the liquid is transferred into a container

To deliver

Glassware that holds and transfers liquid that will deliver the amount measured

High thermal borosilicate or aluminosilicate glass

Glassware routinely used in chemical chemistry should consist of what materials?

Presoaking glassware in soapy water

Highly recommended whenever immediate cleaning is impractical

Volumetric flask

Calibrated to hold one exact volume of liquid and has a round, lower portion with a flat bottom and a long, thin neck with an etched calibration line

Volumetric flasks

Used to bring a given reagent to its final volume with the recommended diluent

Erlenmeyer flasks and griffin beakers

Designed to hold different volumes rather than one exact amount

Erlenmeyer flask

Has a wide bottom that gradually evolves into a smaller, short neck

Griffin beaker

Has a flat bottom, straight sides and an opening as wide as the flat base, with a small spout in the lip

Graduated cylinders

Long, cylindrical tubes usually held upright by an octagonal or circular base and has horizontal calibration marks and is used to measure volumes of liquids

Class A

All laboratory glassware used for critical measurements should be what class?

Pipettes

Type of laboratory equipment used to transfer liquids; they may be reusable or disposable and usually used for volumes of 20 mL of less; larger volumes are usually transferred or dispensed using automated pipetting devices

TC pipette

Pipette that holds or contains a particular volume but does not dispense that exact volume

TD pipette

Pipette that will dispense the volume indicated

Upright

The pipette is held how?

Blowout pipette

Pipette has a continuous etched ring or two small, close, continuous rings located near the top of the pipette and that the last drop of liquid should be expelled into the receiving vessel

Self-draining

Without the continuous etched ring or two small, close, continuous rings, the pipette is called what?

Mohr pipettes

Self-draining pipettes should not be able to touch the fluid in the receiving vessel during drainage, with the exception of what pipette?

Mohr pipette

Pipette that does not have graduations to the tip but the tip should not be allowed to touch the vessel while the pipette is draining

Self-draining pipette

What kind of pipette is a Mohr pipette?

Serologic pipette

Pipette that has graduation marks to the tip

Blowout pipette

What kind of pipette is serologic pipette?

Micropipette

Pipette with a total holding volume of less than 1 mL; it may be designed as either a Mohr or a serologic pipette

Transfer pipettes

Designed to dispense one volume without further subdivisions

Ostwald-folin pipettes

Used with biologic fluids having a viscosity greater than that of water

Blowout pipettes

Ostwald-folin pipettes are what kind of pipette?

Volumentric pipette

Designed to dispense or transfer aqueous solutions and is always self draining

Volumentric pipette

Pipette that has the greatest degree of accuracy and precision and should be used when diluting standards, calibrators or quality control material and should be used once prior to cleaning

Disposable transfer pipettes

May or may not have calibration marks and are used to transfer solutions or biologic fluids without consideration of a specific volume and should not be used in any quantitative analytic techniques

Automatic pipette

Most routinely used pipette in today’s clinical chemistry laboratory

Fixed volume

Pipette associated with only one volume

Variable

Pipette models able to select different volumes are termed what?

Automatic macropipette

Pipette that dispenses greater than 1 mL

Multichannel pipettes

Able to attach multiple pipette tips to a single handle and can then be used to dispense a fixed volume of fluid to multiple wells, such as to a multiwell microtiter plate

Air-displacement pipette

Relies on a piston for creating suction to draw the sample into a disposable tip that must be changed after each use

No

Does an air-displacement pipette’s piston come in contact with the liquid?

Positive-displacement pipette

Operates by moving the piston in the pipette tip or barrel, much like a hypodermic syringe

Dispensers and dilutor/dispensers

Automatic pipettes that obtain the liquid from a common reservoir and dispense it repeatedly

Disposable one-use pipette tip

What tips are designed for use with air-displacement pipette

Glass or plastic

Tips for positive-displacement pipettes are made of straight columns of what?

Gravimetric method

What method is used to calibrate a pipette?

Syringes

Sometimes used for transfer of small volumes in blood gas analysis or in separation techniques such as chromatography or electrophoresis

Hydrate

Many compounds combine with water molecules to form loose chemical crystals. The compound and the associated water are called what?

Anhydrous

When the water of crystallization is removed from the compound, it is said to be what?

Hygroscopic

Substances that take up water on exposure to atmospheric conditions

Moisture

Materials that are vey hygroscopic can remove what from the air?

Desiccants (drying agents)

Materials make excellent drying substances and are sometimes used as what to keep other chemicals from becoming hydrated?

Analytic balances

Required for the preparation of any primary standard and has a single pan enclosed by sliding transparent doors, which minimize environmental influences on pan movement, tared weighing vessel and sample

0.01 mg to 160 g

Weight range for many analytic balances

Electronic balances

Single-pan balances that use an electromagnetic force to counterbalance the weighed sample’s mass and their measurements equal the accuracy and precision of any available mechanical balance with the advantage of a fast response time

Centrifugation

Process in which centrifugal force is used to separate serum or plasma from the blood cells as the blood samples are being processed; to separate a supernatant from a precipitate during an analytic reaction; to separate two immiscible liquids such as lipid-laden sample or to expel air

Mass

Speed

Radius

Centrifugal force depends on three variables":

Revolutions per minute (rpm)

Centrifugal speed is expressed in what?

Relative centrifugal force (RCF) or gravities (g)

Centrifugal force generated is expressed in what?

1.118 × 10 (^-5)

What is the constant of speed of the centrifuge?

Radius

r in RCF equation is what?

Centimeters

RCF radius is expressed in what?