the present invention describes isolation of plasmid dna or nucleic acid material from escherichia coli or other species of microorganisms , or from other sources . the addition of indicator dyes to the alkaline lysis based purification buffers allows for increased ease of visual monitoring of the mixing and lysis steps of the procedure . the yield and quality of plasmid dna is improved and the chance of error is reduced . the practice may be applied to other nucleic acid purification procedures .