Study on Efficiency of Protein Extractants Employed for Human Origin Determination of Blood

Human origin determination is an important aspect of blood grouping analysis in forensic science laboratories. In the present study, protein extractants like gel buffer, ammonia and saline employed for origin determination were evaluated and compared qualitatively and quantitatively for their role in the extraction of proteins from dried blood stained materials of human origin at regular time intervals. Qualitative and quantitative methods employing counter immunoelectrophoresis (CIE) and rocket immunoelectrophoresis (RIE) respectively were used to study the protein extraction efficiency of extractants. Ammonia, compared to gel buffer and saline extracted the proteins effectively. Maximum extraction of proteins was observed in 2-3 hours of sample. CIE demonstrated sharp precipitin bands with all samples of ammonia extractant compared to the samples of counterparts. RIE also revealed greater concentration of proteins in the ammonia extract compared to extracts of gel buffer and saline. These results provide evidence that ammonia serves as a better protein extractant for rapid determination of human blood origin.