Basic Principles And Practices In Clinical Chemistry – Laboratory Equipment And Supplies (MT 315)

Vocabulary flashcards covering reagents, water specifications, glassware/plasticware, pipets, balances, and basic separation techniques from the lecture notes.

Analytical Reagent Grade (AR)

A high-purity chemical grade used for preparing reagents in the clinical laboratory.

ACS

American Chemical Society designation indicating a high-purity AR/ACS standard.

Chemically Pure (CP) Grade

Sufficiently pure for many clinical analyses; does not reveal all impurities.

Spectrograde

An AR-grade chemical suitable for spectrophotometry applications.

Nanograde

A very high-purity AR-grade chemical used in sensitive analyses.

HPLC Grade

High-purity grade suitable for High Performance Liquid Chromatography.

USP/NF Grade

Chemicals meeting US Pharmacopoeia/National Formulary specifications; generally less pure than CP.

Primary Standard (PS)

Highest-purity chemical used to prepare substances of exact concentration; PS must be ≥99.98% pure; working standards ≥99.95%.

Grade A

Primary standards with atomic weight value standards.

Grade B

Ultimate standards.

Grade C*

Primary standards with impurity >0.002%.

Grade D*

Working standards with impurity >0.5%.

Grade E

Secondary standards derived from Grade C standards.

Standard Reference Materials (SRM)

Purified primary standards maintained by NIST/NBS; expensive reference materials.

National Institute of Standards and Technology (NIST)

U.S. organization that provides standardized reference materials (SRMs).

Secondary Standard

Substance of lower purity whose concentration is determined by comparison to a primary standard.

Reagent Water (RGW)

Water suitable for reagent and standard preparation in the lab.

Distilled Water

Water purified by distillation to remove most organic materials.

Deionized Water

Water produced by ion exchange resins, then replaced with H+ or OH- ions.

Type I RGW

Highest-purity RGW used for standard solutions and nanogram-level work or tissue culture.

Type II RGW

RGW used for most routine laboratory determinations.

Type III RGW

RGW used for qualitative measurements; carbon dioxide-free via boiling Type II water.

RGW Carbon Dioxide-Free Water

Water boiled to remove CO2 for analyses sensitive to CO2, ammonia, or O2.

Celsius (°C)

Temperature scale commonly used in laboratories.

Kelvin (°K)

SI temperature scale used in scientific contexts.

Thermometer

Device used to measure temperature; types include liquid-in-glass, electronic (thermistor), and digital.

Liquid-in-Glass Thermometer

Traditional thermometer type using liquid column (e.g., mercury/alcohol) in a glass tube.

Electronic Thermometer

Thermistor-based thermometer or probe for rapid temperature readings.

Digital Thermometer

Electronic thermometer with a digital display for readings.

NIST Reference Thermometer

National Institute of Standards and Technology-certified thermometer used as a calibration standard.

Preventive Maintenance

Scheduled maintenance for laboratory instruments to ensure accuracy and reliability.

Class A Tolerances

Tighter tolerances; preferred for laboratory applications.

Class B Tolerances

Twice the tolerance limits of Class A.

Volumetric Flask (Class A)

Glassware calibrated to hold an exact volume (TC).

TC vs TD

To Contain (TC) holds a volume but does not necessarily deliver exactly; To Deliver (TD) delivers an exact volume.

Erlenmeyer Flask

Conical glassware used to hold varying volumes, not calibrated to a single exact amount.

Griffin Beaker

Beaker-type glassware used for holding liquids; not exact-volume calibrated.

Graduated Cylinder

Glassware with markings to measure approximate volumes, less precise than volumetric flasks.

Borosilicate Glass

Heat- and chemical-resistant glass (e.g., Pyrex, Kimax, Exax).

Corex (Aluminosilicate Glass)

Glass stronger than borosilicate; better resistance to clouding and scratching.

Vycor (High Silica Glass)

Glass with very high silica content for extreme chemical/thermal conditions.

Soft Glass (High Resistance to Alkalis)

Boron-free glassware resistant to strong alkalis but with lower thermal resistance.

Actinic Glass (Low Actinic Glass)

Amber/red glass that reduces light exposure to light-sensitive samples.

Standard Flint Glass

Low-cost soda-lime glass; poor heat resistance; may release alkali.

Polyethylene (Polyolefin)

Inert plastic; resistant to many chemicals; not ideal with concentrated acids.

Polypropylene (Polyolefin)

Autoclavable plastic; more expensive; may discolor with pigments.

Polycarbonate

Strong, clear plastic; not as resistant to bases/oxidizers as polyolefins.

Tygon

Nontoxic flexible tubing (PVC) used for handling chemicals; autoclavable.

TEFLON/PTFE

Inert fluorocarbon resin; extreme temperature resistance; very chemical-resistant.

Polystyrene

Rigid, cheap plastic; non-autoclavable; can release alkali.

Pipets (TD vs TC)

Pipettes designed to deliver exact volumes (TD) or contain volumes (TC).

Mohr Pipet

Graduated transfer pipet with two marks for precise measurements (SD/TD).

Serologic Pipet

Graduated pipet with marks along the stem; can deliver to tip visibility (BO/TD).

Ostwald-Folin Pipet

Micropipet designed for viscous fluids; larger bulb near tip; often TD/BO.

Volumetric Pipet

Pipet calibrated to deliver a single exact volume (TD/VC).

Van Slyke Pipet

Micropipet with thick-walled capillary tubing; delivers precise small volumes.

Sahli’s Pipet

Transfer pipet capable of delivering about 20 µL (TC/RO).

Pasteur Pipet

Untubed transfer pipet without precise volume calibration.

Micropipets

Pipets designed to measure and transfer very small volumes (µL range).

Positive-Displacement Pippet

Automatic pipet where piston contacts liquid; most accurate; ideal for viscous/toxic samples.

Air-Displacement Pippet

Automatic pipet using a piston that does not contact liquid; uses disposable tips.

Pipetting Technique Tips

Pre-wet tips; maintain consistent plunger speed; change tips between samples; use appropriate tips; calibrate regularly.

Meniscus

Curved liquid surface caused by surface tension; reading depends on concave/convex shape.

Lower Meniscus (Concave)

Read volume at the bottom of a concave meniscus when eye level aligns with it.

Upper Meniscus (Convex)

Read volume at the top of a convex meniscus when eye level aligns with it.

Blow-Out

Pipette design where last drop is blown out to ensure complete delivery (etched ring).

Rinse-Out

Pipet that delivers by rinsing contents out after suction.

Cleaning Glassware

Standard sanitization with bleach, acids (HCl/HNO3), cresol; specialized steps for blood clots and metal ion determinations.

Analytic Balances

Balances used for preparing primary standards; high-precision instruments.

Electronic Balances

Single-pan balances using electromagnetic force to counterbalance mass.

Calibration Weights (ANSI/ASTM Classes 1-4)

Standardized weights used to calibrate analytical balances; Class 1 most precise.

NIST Calibration Weights Classes

Class S, M, S-1, P, J weights used for different levels of analytical work.

RCF (Relative Centrifugal Force)

Force calculated for centrifugation: RCF = 1.118×10^-5 × r × rpm^2.

Basic Separation Techniques

Centrifugation, Filtration, Dialysis used to separate components of mixtures.

Centrifuge Types

Horizontal/Swinging-Bucket (3,000 RPM); Fixed-Angle (7,000 RPM); Ultracentrifuge (100,000 RPM); Cytocentrifuge (200–2,000 RPM).