The discovery of chromatin

DEFINITION

Chromatin is the genetic material of the nucleus consisting of deoxyribonucleoprotein that occurs in two forms during the phase between mitotic divisions: as heterochromatin (seen as condensed, readily stainable clumps) and as euchromatin (dispersed, lightly staining or nonstaining material). During mitotic division the chromatin condenses into chromosomes[1].

DISCOVERY

The German biologist Walther Flemming discovered[2] chromatin in 1879 while researching cell division. In his 1879 publication he notes the presence of thread-like substances distributed throughout the cell nucleus and which readily absorbs dyes such as aniline and haematoxylin. Here is an electron micrograph[3] of a rat’s liver cell nucleus (“N is the nucleolus) with its chromatin visible as dark granular clumps:

DISCOVERER

Here is a photograph[4] of Walther Flemming:

1843-1905

Leave a Comment

Your email address will not be published. Required fields are marked *

en_GBEnglish
en_GBEnglish arArabic