Dictionary > Absorbance

Absorbance

Definition
noun
(analytical chemistry)
A logarithmic measure of the amount of light absorbed (at particular wavelength) as the light passes through a sample or substance.
(microbiology)
The measure of the amount of light absorbed by a suspension of bacterial cells or a solution of an organic molecule with the use of a colorimeter or spectrophotometer.
Supplement
Absorbance measurements are often carried out in analytical chemistry, since the absorbance of a sample is proportional to the thickness of the sample and the concentration of the absorbing species in the sample.
Absorbance may be applied in plotting the growth of bacteria in suspension cultures. It may also be used in gauging the purity and concentration of molecules (e.g. proteins) in solution.
Although absorbance does not have true units, it is quite often reported in “Absorbance Units” or AU.
Word origin: L absorbére, equiv. to ab- + sorbére to suck in, swallow + –ance.
Related forms: absorbency (noun).
Synonym: optical density.

Compare: absorption.


You will also like...

Gibberellins and Gibberellic Acid
Gibberellins and Gibberellic Acid

This tutorial describes the role of gibberellin family in plants. Find out the effects of gibberellin on plant growth an..

Evolution of Life - Ancient Earth
Evolution of Life – Ancient Earth

Autotrophs flourished, absorbing carbon and light. Soon after, primitive life forms that could assimilate oxygen thrived..

Chemical composition of the body
Chemical Composition of the Body

The body is comprised of different elements with hydrogen, oxygen, carbon, and nitrogen as the major four. This tutorial..

complete-dominance
Dominance

This tutorial presents Gregor Mendel's law of dominance. Learn more about this form of inheritance and how it can be pre..

Plant meristem
Plant Meristems and Growth

In plants, growth occurs in meristems, which are the site of repeated cell division of unspecialized cells. These cells ..

Still Water Animals
Still Water Animals

Animals living in aquatic habitats have diversified and evolved through time. They eventually occupy ecological niches a..