use of spectrophotometer in indentification of bloodstains: abnormal haemoglobins

ABSTRACT

The present work was designed to apply an easy as well as low- cost method forboth identification and aging of human blood stains with abnormal hemoglobins. This study was conducted on 68 blood stains. Hemoglobin as well as hemoglobinelectrophoresis were done for the whole blood samples. The remaining of eachblood sample was then spread, in equal amounts, on cotton fabrics, dried atroom temperature, and stored in filter paper envelops. Blood hemoglobincurves were drawn and the alpha ratio was calculated for all the specimens atintervals of 1, 3, 7, 14, 30 and 60 days. There was a significant differencein the mean alpha ratio between subjects with abnormal hemoglobins whencompared with the control group. There was as well a significant negativecorrelation between the mean alpha ratio and time in all the studied groups. The present work showed that an absorption spectrum of a minute speck of bloodcan prove that the substance under examination is blood. Furthermore, therate at which the alpha ratio decreases might be of more value in aging ofblood stains than the alpha ratio itself