A modified methodology for generation of dna profile from blood mixed with soil

The development of a complete DNA profile from biological material, specifically blood mixed with soil, is always a challenging job, as the available biological materials become diluted, contaminated, and destroyed upon mixing with earth materials. Apart from that, the soil or mud contains a range of inhibitors, free radicals, metallic ions, acids, etc., which strongly interfere with the sensitive enzymatic reactions during the process of DNA profiling and prevent the examiner from getting a complete and clear DNA profile from such evidence materials. In order to avoid the contaminants and other chemical and physical inhibitors available in soil, mud, or other earth materials, a new methodology was developed and employed in the DNA profiling unit of CFSL (CBI), New Delhi. The procedure involved three distinct steps. In step one, the blood cells were separated from the soil sample via dilution and highspeed centrifugation. In the second step, the cells were digested by adding organic buffers and incubation, and in the third step, the separation of DNA was carried out by utilising an automated DNA extraction system (EZ1 XL). Further, the extracted DNA was subjected to multiplex amplification and genotyping to obtain a complete DNA profile.