NCJ Number
246514
Journal
Forensic Science International: Genetics Volume: 10 Dated: May 2014 Pages: 17-22
Date Published
May 2014
Length
6 pages
Annotation
This article explains the process of performing DNA extraction for short tandem repeat typing from mixed samples using the anti-human leukocyte CD45 and antibodies from the ABO blood group.
Abstract
Evidence collected at crime scenes often contains a mixture of various cells from one person. Determining how many contributors are presented in the DNA profile of the collected samples can be difficult to ascertain. This article explains a process for performing DNA extraction for short tandem repeat (STR) typing from mixed samples using the anti-human leukocyte CD45 and antibodies from the ABO blood group. A test case was performed using a whole blood sample containing an equal contribution from three men of different blood types - A, B, and O. Cell suspensions of the samples were created, and, using magnetic separation, leukocytes were collected from the cell suspensions using whole blood columns. Centrifugal separation of leukocytes by ABO antibody was also performed on the samples. Using the Maxwell 16 System, DNA was extracted from the resulting cell pellets, and the DNA was typed using the PowerPlex Y23 System and Identifiler Kit. The results showed that the target DNA could be detected accurately as low as 1:512 mixed ratio, regardless of the large amount of background DNA present in the sample. These results demonstrate that this method can be useful for identifying DNA in mixed evidence samples. Further research is suggested. 5 figures and 18 references