α-globin messenger ribonucleic acid as a molecularmarker for determining the age of human bloodspots in different temperatures

Background: analyzing recovered evidence, such as blood which is one of the most encountered types of biological evidence, can provide information to establish the definite time when a crime was committed. this study aims to investigate the timeand temperature-related effects on human bloodstain’s α-globin messenger rna expression and to estimate the bloodstain’s age using α-globin mrna. methods: a total of 22 blood samples were collected from healthy middle-aged volunteers (12 women and 10 men). after preparation, the samples were exposed to temperatures of 4°c, 24°c, and 40°c. next, the mrna expression of the α-globin gene was quantified by real-time rt-pcr at different time intervals of 0, 30, 90, and 150 days. results: the α-globin gene expression showed the highest mean values by 0 day and at 4°c and the lowest mean values by 150 days and at 40°c. samples from male participants showed higher mean values of α-globin gene expression compared to their female counterparts. a significant negative correlation was detected between α-globin gene expression and time interval. meanwhile, a regression equation was formulated to estimate the time interval using the α-globin gene concentration. conclusion: α-globin mrna could be a useful marker to estimate the age of human blood spots.