BACKGROUND Genetic transformation involves the alteration of genes when cells take up uncoded Deoxyribonucleic acid from the extracellular environment. OBJECTIVE To render competency to untransformeed bacterial cells using the Calcium chloride cation. METHODS The heat-shock method perforates the cell membrane to make it permeable for the foreign DNA to penetrate easily. RESULTS Viable colonies will take up the gene construct, cloned into a plasmid, thus making the bacterial cells capable of replicating the desired sequence, in sufficient numbers CONCLUSIONS Competent bacterial cells can be used in diverse molecular analyses, such as plant genetic transvia Agrobacterium mediated transgenic system.