MLLT 106 – Introduction to Clinical Chemistry: Lessons 6 Definitions

What is absorbance (A)?

A measure of the quantity of light absorbed by a sample, inversely proportional to percent transmittance.

What does amperometry measure?

It measures the current flowing through an electrochemical cell due to an oxidation-reduction reaction with a constant potential applied.

What is Beer’s law?

A law stating that the concentration of a substance is directly proportional to the amount of light absorbed, and inversely proportional to the logarithm of the transmitted light.

What is an ion-selective electrode?

A type of electrochemical sensor that measures the activity of specific ions in a solution.

What does the light spectrum refer to?

The range of all possible frequencies of electromagnetic radiation, including visible light.

What is the function of a monochromator?

A device that isolates a narrow band of wavelengths from a broader spectrum of light.

What does nephelometry measure?

It measures the amount of light scattered by particles in a solution, typically at an angle.

What is percent transmittance (%T)?

The ratio of the light transmitted through a sample to the incident light, expressed as a percentage.

What does a reflectance photometer do?

It measures the amount of light reflected from a sample surface.

What is solid-phase chemistry?

A method where reagents are pre-impregnated onto a test strip or film, allowing reactions to occur on a solid support.

What is the purpose of a spectrophotometer?

An instrument used to measure the absorbance or transmittance of light through a sample at specific wavelengths.

What is photometry?

The measurement of light, often involving the use of filters to select specific wavelengths.

What is spectrophotometry?

The study of interactions between light and matter, often for quantitative analysis.

What is a standard calibratrice curve?

A graph plotting the responses of known concentrations of an analyte against their measured values, used to determine concentrations of unknown samples.

What constitutes a standard solution?

A solution containing a precisely known concentration of a substance, used for calibration or comparison.

What is turbidimetry?

A technique that measures the decrease in light transmission due to scattering by particles in a solution.

What is chemiluminescence?

A technique that detects light emitted as a result of a chemical reaction.

What is chromatography?

A separation technique that separates components of a mixture based on their differential distribution between a stationary and a mobile phase.

What does a colorimeter measure?

It measures the color intensity of a solution, often using filters to select specific wavelengths of light.

What is coulometry?

An electrochemical method that measures the total charge passed through an electrochemical cell to complete a reaction.

How does electrophoresis work?

It separates molecules, like DNA or proteins, based on their size and electrical charge using an electric field.

What is flow cytometry?

A technique that analyzes and sorts cells or particles in a fluid stream by passing them through a laser beam.

What is an immunoassay?

A biochemical test that measures the presence or concentration of a substance using the specificity of an antibody-antigen reaction.

What is immunofluorescence?

A technique that uses fluorescently tagged antibodies to visualize specific antigens in cells or tissues under a microscope.