Abstract

THE EFFIECIENT METHOD FOR DNA EXTRACTION FROM BLOOD SPOT ON JEANS

Rasha Sadeq Ameen*

ABSTRACT

When a crime or other incident takes place, clothing items are one of the most common types of evidence that present or left behind in the crime scenes, and can become directly involved in the case itself. Blood sample was collected from (5) voluntaries and spotted on three different color of blue jeans at different time (directly, after 2 and 4 weeks), the DNA was extracted by using the most commonly method (Chelex® 100, organic phenol-chlorophorm, Wizard® Genomic DNA Purification Kit (Promega, USA). Results indicated that the organic phenol- chlorophorm method cannot be used for DNA extraction from the dark blue type of the jeans while there is decrease in DNA concentration with increase in time of spot dry in both chelex and kit methods, in the case of the medium blue type of the jeans the organicmethod gave the best result with mean DNA concentration (4.306 ng/μl) from direct treatment and (3.145 ng/μl) after 2 week of drying, also the phenol- chloroform organic method is the best method for the extraction of DNA from light blue jeans directly with 12.162 ng/μl mean concentration of DNA followed by the kit method with 1.19 ng/μl mean concentration of DNA, these value was become 3.848 ng/μl and 0.0194 ng/μl respectively after 2 week of extraction. After 4 week of drying the spot there is slightly difference in the amount of the mean concentration of DNA obtained from chelex and kit method while there is no DNA obtained when using the organic method for extraction. From that it has been concluded that there is a correlation between the obtained DNA concentration and the color of the jeans in which the blood spot left on.

Keywords: bloodspots, phenol-chlorophorm organic, chelex® 100, DNA extraction, jeans.