ABSTRACT
The primary requisite for the extraction of nuclei is to isolate them in normal condition in adequate amounts and to keep the chromatin in an undamaged state. In the indirect mass isolation technique, the general stages include the disintegration of the cytoplasm through mechanical or chemical means, keeping the nucleus intact, followed by filtration through mesh or cheesecloth, differential centrifugation in suitable liquids and sedimentation. For the analysis and quantitation of chromosomes and chromosome components, chemical isolation is the other alternative, in addition to in situ technique as described elsewhere. Chromosome isolation often becomes necessary for identification of functional segments and mapping of gene loci. Purification of chromosomes from plants may involve isolation of a single morphologically distinct chromosome through micromanipulation or thepreparation of pure chromosome suspension. Isolation and purification of nuclear deoxyribonucleic acid are essential for a variety of reasons.
