How does a colorimetric assay work?

Colorimetric assays use reagents that undergo a measurable color change in the presence of the analyte. A similar colorimetric assay, the Bicinchoninic acid assay, uses a chemical reaction to determine protein concentration. Enzyme linked immunoassays use enzyme-complexed-antibodies to detect antigens.

What is meant by colorimetric analysis?

Colorimetric analysis is a method of determining the concentration of a chemical element or chemical compound in a solution with the aid of a color reagent. It is applicable to both organic compounds and inorganic compounds and may be used with or without an enzymatic stage.

What is colorimetry and why is it used?

colorimetry, measurement of the wavelength and the intensity of electromagnetic radiation in the visible region of the spectrum. It is used extensively for identification and determination of concentrations of substances that absorb light.

What is colorimetric Elisa?

Colorimetric ELISAs require a standard microplate reader to detect the color change reaction between the enzyme label and substrate. The reader sends a wavelength, typically 450 nm, through each well to determine the optical density, or “OD” reading of the samples.

What is an example of a colorimetric assay?

380 nm – 780 nm). Examples include colorimetric protein determination (Brad- ford, Lowry, BCA), cytotoxicity assays, detection of fructose in seminal plasma [1] as well as enzymatic determinations, such as phosphatase assays, alpha glucosidase assays or beta-galactosidase assays [2], to name a few.

What is a colorimetric indicator?

When colorimetric indicators are used, the optode ends with a mirror that focuses back the transmitted light into the central sensing fiber, keeping the information of the optical absorption of the dyed disc.

What is the principle of colorimetry?

The working principle of the colorimeter is based on Beer-Lambert’s law which states that the amount of light absorbed by a color solution is directly proportional to the concentration of the solution and the length of a light path through the solution.

What are the benefits of using a colorimeter?

Compared with other methods, the colorimetric method has some obvious advantages, such as low cost, simple instruments (or, in the case of naked eye detection, no instruments), and can be qualitatively or semiqualitatively identified by the naked eye. However, colorimetry is generally less sensitive.

Is ELISA A colorimetric assay?

The most common type of ELISA detection uses a colorimetric assay. Generally, horseradish peroxidase (HRP-) or alkaline phosphatase (AP-) conjugated antibodies are used in combination with a chromogenic substrate (eg, TMB) solution.

What is chemiluminescence method?

Chemiluminescence (CL) is defined as the emission of electromagnetic radiation caused by a chemical reaction to produce light. Chemiluminescence immunoassay (CLIA) is an assay that combine chemiluminescence technique with immunochemical reactions.

Is Elisa A colorimetric assay?

How does a colorimetric sensor work?

Colorimetry is another well-known sensing principle that is also widely used in commercial gas sensors. It detects a color change associated with a specific chemical reaction between an analyte and sensing materials. When the exposure time is limited to 20 s, the sensor chip can be used 150 times before replacement.