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...

Buttress roots
Roots

This study guide tackles plant roots in greater detail. It delves into the development of plant roots, the root structur..

Cell structure
Cell Structure

A typical eukaryotic cell is comprised of cytoplasm with different organelles, such as nucleus, endoplasmic reticulum, G..

Wart-like leaf galls on grape leaves
Plant Cell Defense

Plants protect themselves by releasing hydrogen peroxide to fight against fungal invasion. Another way is by secreting c..

human respiratory system
Respiration

The human respiratory system is an efficient system of inspiring and expiring respiratory gases. This tutorial provides ..

Electromagnetic spectrum of a brain
Sleep and Dreams – Neurology

While learning and intelligence are associated with the functions of a conscious mind, sleep and dreams are activities o..

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 ..

Related Articles...

No related articles found

See all Related Topics