Dictionary > Optical density

Optical density

Definition
noun
(1) The measure of transmittance of an optical medium for a given wavelength. The higher the OD the lower the transmittance, the higher protection factor by a filter (e.g. goggles, viewing windows, etc.).
(2) 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 colourimeter or spectrophotometer.
Supplement
In microbiology, the values can be used to measure turbidity, which in turn is used to estimate the number of bacteria (or concentration of molecules like proteins) in a solution.
Abbreviation: OD
Synonym: absorbance.

See also: absorption.


You will also like...

Sensory systems
Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal ..

Schematic diagram of bacterial lactose operon
Gene Action – Operon Hypothesis

Learn how the way genes control and determine every aspect of the body. This lesson uses lac operon as an example. ..

..

Freshwater aquatic plankton
Freshwater Communities & Plankton

Planktons are microscopic organisms that live suspended in aquatic habitats. There are two groups: the phytoplanktons an..

Transpiration
Water in Plants

The movement of molecules (specifically, water and solutes) is vital to the understanding of plant processes. This tuto..

river
Running Water Freshwater Communities

This tutorial introduces flowing water communities, which bring new and dithering factors into the equation for possible..

human brain structure
The Conscious & Unconscious Nervous System

This tutorial elaborates on how the nervous system works, particularly at the tissue level of the brain. There are three..

Related Articles...

No related articles found

See all Related Topics