Laboratory Fundamentals and Analytical Concepts (VOCABULARY flashcards)

Vocabulary flashcards covering key lab concepts, equipment, processes, and measurement principles from the provided lecture notes.

Director of the Laboratory

The Pathologist who typically serves as the director of the entire laboratory; usually holds an M.D. or D.O.

MLS (Medical Laboratory Scientist)

Highest level of generalist staff; typically requires a 4-year bachelor’s degree; replaced MT and CLS designations in 2009.

MLT (Medical Laboratory Technician)

Generalist staff level requiring a 2-year associate degree.

CLA (Clinical Laboratory Assistant)

Staff level representing a 1-year certification program.

Laboratory Administration

Includes roles such as lab/department managers, area managers, and section supervisors.

Main Divisions of the Lab

Anatomical Pathology, Clinical Pathology, and Support services.

Area Managers/Specialists

Specialized areas (e.g., Microbiology, Hematology, Blood Bank, Clinical Chemistry, Immunology) that may have their own managers.

Accreditation

Voluntary process assessing a facility/program to ensure competence and public protection; non-participation may affect reimbursement.

CAP (College of American Pathologists)

Accredits about 34% of labs; internationally recognized; inspectors are laboratory professionals; exceeds CLIA compliance.

TJC (The Joint Commission)

Formerly JCAHO; accredits about 23% of laboratories; evaluates hospitals, clinics, reference labs, and more.

COLA

Private accreditation organization started in 1988; accredits about 40% of laboratories.

A2LA

Nonprofit organization used to meet CLIA regulations; deemed status from CMS (2014); recognized for ISO 15189.

CLIA-67

Early federal law establishing regulation of laboratories, limited to interstate commerce.

CLIA-88

1988 amendments expanding federal authority to regulate any lab testing human specimens for diagnosis, prevention, or treatment, regardless of where the test is performed.

CLIA Funding Model

User-fee funded government program; facilities must cover costs; certification required even for cash-only or non-Medicare/Medicaid facilities.

Waived Tests

FDA-cleared tests for home use; simple with minimal risk; often used in point-of-care testing.

Moderately Complex Tests

Most laboratory tests fall into this category of complexity.

Highly Complex Tests

Testing procedures requiring a high degree of experience and technical training.

Provider-Performed Microscopy (PPM)

A CLIA complexity category; exact description not detailed in the provided source.

Pipette

A hollow tube used to measure and deliver small volumes of liquids, typically up to 20 mL.

Mouthpiece & Pipetting Safety

Mouthpiece prevents direct mouth pipetting; safety device used.

TD Calibration

Stands for 'to deliver'; calibrated to deliver a measured amount; accounts for wetting; not rinsed.

TC Calibration

Stands for 'to contain'; holds a specific volume; traditionally requires rinsing to deliver full volume.

Blow Out (pipettes)

If a TD pipette has double frosted/etched bands near the mouthpiece, the last drop is blown out.

Volumetric Pipette

Bulb/stem with a single calibration line; measure a single fixed volume; highly accurate.

Serological Pipette

Straight bore; graduations to tip; most are TD and should be blown out; measures reagents.

Mohr Pipette

Straight bore; last calibration line above the tip; marked TD but never with double etched bands; should not be blown out.

Ostwald-Folin Pipette

Similar to volumetric but with a large bore; frosted bands; must be blown out.

Tolerance

Expression of pipette accuracy; given as an error amount or percentage; smaller is better.

Calibration Temperature

Temperature (often 20°C) at which a pipette is calibrated; colder liquids yield smaller volumes.

Microliter Conversion

1.0 mL = 1000 µL; microliter pipettes are used for microliter measurements.

Condenser

Located below the stage; focuses light onto the specimen; adjusted to match the objective.

Iris Diaphragm

Adjustable condenser component controlling the size of the light cone; closer increases contrast for unstained material.

Objectives

Lenses above the stage on the nosepiece; provide initial magnification (e.g., 10X, 40X, 100X).

Oculars

Lenses in the eyepiece; typically magnify by 10X.

Overall Magnification

Product of objective magnification and ocular magnification.

Theoretical Maximum Magnification

Magnification limit where image cannot be clearly resolved; often objective NA × 1000.

Resolving Power

Ability of the lens system to show detail of the original object.

Coarse Adjustment

Moves stage relative to objective for rough focus.

Fine Adjustment

Precise, slow focusing near the final focus.

Parfocal

When objectives are rotated, the specimen remains in focus or nearly so.

Stage

Platform that holds the slide; may have a mechanical stage for movement.

Carrying Technique

Hold the arm upright with one hand and support the base with the other.

Cleaning Material

Use only lens paper for lenses; avoid towels to prevent scratches.

Oil Immersion

Apply a drop of immersion oil between specimen and 100X objective to increase NA and resolving power.

Dry Objective Rule

10X and 40X objectives must not contact oil or immersion fluids.

Starting Focus

Begin with 10X (low power); approach the specimen with the coarse adjustment to ~0.5 cm or less above the slide.

Focusing Direction

Look through the ocular and use coarse focus to bring image into view.

Condenser Adjustment for Stained Material

Condenser diaphragm opened to maximize resolution.

Condenser Adjustment for Unstained Material

Condenser or iris diaphragm closed to reduce light and increase contrast.

Storage Procedure (Microscope)

Clean, wipe oil from 100X, center stage, resume low power, and rotate to 10X before storage.

Pre-analytical Phase

All variables and processes before the sample is analyzed; errors here affect reliability.

Analytical Phase

All variables and processes during the test; errors here affect accuracy/imprecision.

Post-analytical Phase

All variables and processes after obtaining a test result.

Rationale for Patient Identification

Critical to ensure testing is performed on the RIGHT PERSON every time.

Specimen Collection Rationale

Minimize pre-analytical variables to improve reliability (e.g., avoid clotted/hemolyzed samples).

Specimen Labeling Rationale

Proper labeling prevents post-analytical errors like reporting results for the wrong person.

Recording Initials/Date/Time

Helps track pre-analytical variables and ensures timely processing.

Specimen Delivery (Transport)

Delivery protocols must maintain appropriate storage temperature to ensure timely results.

Verification/Logging in (Processing)

Verification in the central processing area supports pre-analytical controls.

RCF (Relative Centrifugal Force)

Formula relates rotor radius and RPM to G-force: RCF = 1.12 × radius × (rpm/1000)^2.

G Force

Another term for RCF; the centrifugal force acting on a sample.

Beers Law (Beer-Lambert Law)

Absorbance is proportional to concentration when measuring a single reaction product in a cuvette of fixed diameter.

Absorbance (A)

Light absorbed by a solution; proportional to concentration; also called Optical Density.

Transmittance (%T)

Proportion of light that passes through a solution; inversely related to absorbance.

Beer-Lambert Law Limitation: Linear Range

Only valid within the established range of linearity; outside this range, results are unreliable.

Beer-Lambert Law Limitation: High Absorbance

If absorbance is higher than the last standard, the sample must be diluted and reanalyzed.

Spectrophotometer Error Range

Best accuracy when readings fall within 20–80% T or 0.1–0.7 A.

Spectrophotometry Components

Light source, collimating lenses, wavelength selector, slit, cuettes, photodetector, readout device, and microprocessor.

λmax (Wavelength of Maximum Absorbance)

Wavelength at which a reaction product shows the highest absorbance for maximum sensitivity.

Interfering Compounds

Substances like hemoglobin, bilirubin, and lipemia that alter measurements by absorbing/scattering light.

Cuvette

Sample holder in spectrophotometry; must be clean, unscratched, and matched in size.

Reflectance Photometry

Measures light reflected from a colorimetric reaction; used in quantitative tests.

Transmission Spectroscopy

Measures light transmitted through a colored solution to determine concentration.

Reference Interval

Statistically normal range used to categorize a result as normal; population-based.

Clinical Decision Limit

Threshold value (cutoff) used to indicate disease presence; differs from the reference interval.

Sensitivity

Probability that a diseased person tests positive; aim is high sensitivity.

Specificity

Probability that a non-diseased person tests negative; aim is high specificity.

Positive Predictive Value (PPV)

Probability that a positive test correctly indicates disease.

Negative Predictive Value (NPV)

Probability that a negative test correctly indicates absence of disease.

Prevalence

Proportion of diseased individuals in the tested population; affects predictive values.

Test Efficiency

Overall measure of accuracy considering both positive and negative results.

Controls (Quality Control)

Known-value materials used to verify accuracy and precision of a test system.

Control Range

Acceptable concentration range a control material must achieve; helps verify system reliability.

Neubauer Hemocytometer

A counting chamber divided into 9 large squares; 0.1 mm depth for cell counting.

WBC Counting Area

Four large corner squares used to count white blood cells; total volume per count ~0.4 µL.

RBC/Platelet Counting Area

Center square/counts for RBCs and the entire center square for platelets.

Buffy Coat

Layer after centrifugation containing white cells and platelets between plasma/serum and packed red cells.

Plasma vs Serum

Plasma is blood fluid with anticoagulant; serum is fluid after clotting (lacks fibrinogen).

EDTA

Ideal anticoagulant for WBC counts; prevents clotting by chelating calcium.

Heparin

Anticoagulant to avoid for some tests (can cause blue background staining in smears).

WBC Reference Interval (Adults/African Descent)

Adults: 4.5–11.0 x 10^3 WBC/mm^3 (Caucasians); 3.0–9.0 x 10^3 (African descent).

Dilution (General)

Mixing solute with solvent to reduce concentration; expressed as a ratio (e.g., 1:5).

Diluent (Solvent)

Liquid used to make a solution less concentrated (e.g., saline).

Serial Dilution

Series of progressively more diluted solutions used to reach very low concentrations.

Cuvette Matching

Using cuvettes of the same size throughout the procedure to prevent error.

Buffy Coat vs Plasma/Serum

Buffy coat is the white cell/platelet layer after centrifugation; plasma/serum are the liquid components.

Beer's Law Calculation (A = abc)

Absorbance equals the product of molar absorptivity, path length, and concentration.

λmax Selection

Choosing the wavelength with maximum absorbance for each assay.

Interference Avoidance (Wavelengths)

Avoid wavelengths absorbed by interfering substances (e.g., 575 nm for hemoglobin).