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More methods for extraction of total cell DNA:
From grinding frozen plant cell or simple detergent treatment for animal cell we can get cell components.
Plants and animals have carbohydrates etc other than bacterial cell.
The plant carbohydrate are not removed by phenol extraction method.
A detergent called CTAB (cetyl trimethyl ammonium bromide) forms insoluble complex with nucleic acid.
This complex gets pecipitated leaving carbohydrates and protein and other contamination behind.
This is centrifuged and resuspended in 1M NaCl which breakdown complex.
Nucleic acid is now concentrated by ethanol and RNA removed by ribonuclease.
Another method:
Guanidium thiocynate has two properties
1. It denatures and dissolves all biochemical other than nucleic acid and can be used to release DNA from any type of cell or tissue.
2. In presence of Guanidium thiocyanate DNA binds tightly to silica plates.
Silica placed in column and cell extract is added.
DNA recovered by adding water due to destabilization of interaction between silica and DNA.
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