ANALYTICAL TECHNIQUES AND AUTOMATION IN CLINICAL CHEMISTRY 1 LABORATORY

Vocabulary flashcards covering key terms and definitions from the lecture notes on analytical techniques and automation in the clinical chemistry lab.

Automation in the clinical laboratory

Use of automated instruments and processes to increase throughput and reduce manual error in testing.

Advantages of automation

Increases tests performed, reduces inter-lab variation, and minimizes manual errors (pipetting, calculation, transcription).

Continuous Flow Analyzer

Instrument that pumps liquids through a system of tubing; samples flow in a common pathway with regular air bubbles for separation and cleaning.

Centrifugal Analyzer

Uses centrifugal force to transfer specimen and reagents; liquids in separate cuvettes; rotor spins at ~1000 rpm.

Discrete Analyzer

Measures one test on one sample at a time with small sample volume (2–6 microliters) using magnetic stirring.

Batch Testing

All samples are loaded at once; a single test is conducted on each sample.

Parallel Testing

Multiple tests are analyzed concurrently on each specimen.

Random Access Testing

Tests can be run in any order on any sample; prioritizes STAT samples.

Sequential Testing

Multiple tests analyzed one after another on each specimen.

Open Reagent System

System that can utilize reagents from non-manufacturer sources.

Closed Reagent System

System that uses only the manufacturer's reagents.

Spectrometry

Analytical technique that measures how substances interact with light to determine concentration or identity.

Luminescence

Emission of light by a substance not caused by heat; includes fluorescence and chemiluminescence.

Electroanalytic Methods

Techniques based on electrical properties (e.g., electrophoresis, electrochemistry, potentiometry, voltammetry).

Chromatography

Separation technique based on differential distribution of substances between mobile and stationary phases.

Colorimetry

Measurement of color intensity to determine concentration, often via absorbance.

Spectrophotometry

Measurement of how much light is absorbed by a sample at a given wavelength.

Flame Emission Spectrophotometry

Measurement of light emitted by atoms excited in a flame to determine element concentrations.

Atomic Absorption Spectrophotometry

Measures light absorbed by atoms in a flame or furnace to quantify elements.

Fluorescence

Luminescent emission at longer wavelengths after absorption of higher-energy light; used in fluorometric assays.

Chemiluminescence

Emission of light as a result of a chemical reaction without external light excitation.

Nephelometry

Measurement of scattered light at an angle to quantify antigen–antibody complexes or particles.

Antigen–Antibody Complex

Large immune complexes that scatter light; central to nephelometric assays.

Nephelometer

Instrument that detects scattered light to quantify analytes based on antigen–antibody interactions.

Turbidimetry

Measurement of the reduction in transmitted light due to particle formation in a solution.

Beer's Law

Relation where absorbance is proportional to concentration of an absorbing species in a solution.

Absorbance

Logarithmic measure of how much light is absorbed by a sample at a given wavelength.

Transmittance

Fraction of light that passes through a sample; inverse of absorbance in Beer's Law context.

Wavelength

Distance between successive peaks of a wave, measured in nanometers (nm) for light.

Planck’s formula (E=hv)

Energy of a photon equals Planck’s constant times its frequency.

Monochromator

Optical device that isolates a specific wavelength from a light source.

Prisms

Wedge-shaped glass/quartz pieces used to disperse light into a spectrum in some monochromators.

Diffraction Gratings

Monochromator element with grooves that separate wavelengths for higher resolution.

Filters

Simple, inexpensive wavelength-selection elements used in monochromators or to reduce stray light.

Holographic Gratings

High-resolution gratings used in monochromators for precise wavelength selection.

Entrance Slit

Slit at the start of the monochromator that limits stray light entering the system.

Exit Slit

Slit at the end of the monochromator that sets the width of the transmitted light (bandpass).

Cuvette

Sample container where measurement of light transmittance or absorbance occurs.

Photodetector

Device that converts transmitted light into an electrical signal.

Photocell

Basic light detector; barrier or photovoltaic cell.

Phototube

Vacuum tube detector with anode and cathode for light detection.

Photomultiplier Tube (PMT)

Highly sensitive detector that amplifies weak light signals, common in UV/IR measurements.

Photodiode

Detector that measures light across multiple wavelengths with excellent linearity.

Light Source (Continuum)

Broad-range source; examples include tungsten (visible/IR), deuterium (UV), xenon (spectrofluorometers).

Line Source

Source that emits discrete lines/bands; often mercury-vapor for UV, others for fluorescence.

Single Beam Spectrophotometer

Absorption spectrometer that measures one sample at a time; simpler design.

Double Beam Spectrophotometer

Splits light to pass through both sample and reference cuvettes to compensate for source fluctuations.

Double Beam in Time

One light path with a mirror system alternately directing light to sample and reference over time.

Double Beam in Space

Two separate photodetectors measure light simultaneously from sample and reference paths.

Beers Law Reciprocal Concepts

Absorbance increases with concentration; transmittance decreases as color intensity rises.

Stains for Protein Visualization

Dyes used to visualize protein bands after electrophoresis (e.g., Ponceau S, Coomassie Blue, Amido Black).

Ethidium Bromide

Carcinogenic DNA stain used to visualize nucleic acids in gel electrophoresis; fluorescent under UV.

Densitometry

Quantitative densitometric analysis of protein bands from electrophoresis.

Fractions of Separated Proteins

Albumin, Alpha1, Alpha2, Beta, Gamma globulins separated in electrophoresis.

Planar Chromatography

2D diffusion-based chromatography on flat supports (Paper, Thin-Layer).

Paper Chromatography

Planar chromatography using Whatman paper as the sorbent for separation.

Thin Layer Chromatography (TLC)

Planar chromatography on plastic plates; separates small molecules like drugs.

Column Chromatography

Chromatography in a 3D system using a column; includes GC, GC-MS, HPLC.

Gas Chromatography (GC)

Chromatography of volatile compounds based on boiling points.

Gas Solid Chromatography

GC variant using a solid phase to absorb compounds.

Gas Liquid Chromatography

GC variant where solute partitions between gas mobile phase and liquid stationary phase.

Liquid Chromatography (LC)

Separation of solutes between a liquid mobile phase and stationary phase; includes HPLC.

High-Performance Liquid Chromatography (HPLC)

Fast, high-resolution LC using pressure to separate drugs, hormones, and variants.

LC-MS

Liquid chromatography coupled with mass spectrometry; confirms non-volatile analytes.

Mass Spectrometry (MS)

Technique that fragments and ionizes molecules to determine structure and mass.

GC-MS

Gas chromatography coupled with mass spectrometry; gold standard for drug testing.

MS/MS

Tandem mass spectrometry; highly sensitive confirmation for certain analyses.

Nuclear Magnetic Resonance (NMR) Spectroscopy

Technique to determine molecular structure using magnetic properties of nuclei.

Fluorometer

Instrument that measures fluorescence emission from a sample.

Fluorophore

Organic compound that emits fluorescence when excited.

RT-PCR (Real-Time PCR) Fluorometry

PCR technique that measures real-time fluorescence to quantify DNA amplification.

Quenching

Reduction of fluorescence due to environmental factors (pH, temperature, quencher presence).

Thermal Cycler

Instrument that cycles temperatures for PCR amplification.

Auramine-Rhodamine

Fluorescent dye with affinity for Mycobacterium in fluorometric assays.

Calcofluor White

Fluorescent dye that binds to fungi or yeast cell walls.

Acridine Orange

Fluorophore that binds DNA; used to stain nucleic acids.

Chemiluminometer

Instrument detecting chemiluminescence; often a luminometer without a light source.

Osmometer

Instrument that measures osmolarity via colligative properties.

Osmolarity

Total solute concentration per liter of solution.

Colligative Properties

Physical properties (osmotic pressure, bp, fp, vapor pressure) depending on solute particles.

Ion-Selective Electrode (ISE)

Electrochemical transducer responding to a specific ion; highly sensitive and selective.

ISE Membranes

Membranes selective for specific ions: Glass, Aluminum Silicate, Valinomycin Gel, Organic Liquid.

Direct vs Indirect ISE

Direct uses diluted sample; indirect uses undiluted sample.

Pipet Classification by Calibration

Volumetric vs Serologic/Graduated vs Ostwald-Folin, Pasteur, etc.

Blow-out vs Self-draining Pipets

Blow-out pipets deliver last drop; self-draining use gravity to deliver.

Transfer Pipets

Pipets designed to move liquids between containers; includes volumetric and serologic types.

Ostwald-Folin Pipets

Pipets used for viscous fluids with etched rings; deliver exact volumes with force.

Micropipettes

Pipettes capable of dispensing very small volumes (<1 mL).

Acid Dichromate

Cleaning solution used to clean glassware.