The isolation of nucleic acid from a cell involves breaking of cell wall and cell membrane either using physical methods or chemicals methods. The complexity of isolation of DNA from a cell depends upon the rigidity of the cell wall. Plant cells, being most rigid, are not easily broken and therefore both physical as well as chemical methods are used to lyse the cell walls. The purification is an essential step as it will make nucleic acid free from other contaminants present in the cell. The quality of nucleic acid depends upon the efficacy of the purification.