The Cast-Off Cell Collecting Method For Contact Samples Affects STR Typing Rate

Objective: The purpose of this dissertation is to explore the feasibility of using short tandem repeat(STR) typing and the effect of different methods of cell sampling on the detection of STR typing.Methods: STR DNA genotyping was performed by using the method of wiping and cutting off the DNA samples of the four kinds of different materials, and together with the actual cases detections on the cable connector and poison dart exfoliated cells of STR classification data, we ought to screen high detection rate of exfoliated cells collection.Results: In the swabbing method collect cellophane tape with exfoliated cells for DNA STR parting detection group, 0 cases(0%) were checked when detected more than 12 loci, and only 4 cases(25%) were checked out 7 loci, whit atlas peak in 200-400 relative fluorescence units(RFU); in cut-off method group, 10 cases(100%) were checked out for more than 12 loci, and atlas peak more than 1000 rfu. That swabbing method collect exfoliated cells on cotton gloves for DNA STR parting detected more than 12 loci in 1 case(10%), totally detected 78 loci, and the atlas peak in 600-1000 rfu; cut method collect cotton gloves for DNA STR parting detected more than 12 loci in 10 cases(100%), and atlas peak more than 1000 rfu. That swabbing method collect logs pencil exfoliated cells for DNA STR parting detection more than 12 loci 0 cases(0%), totallt detected 8 loci, atlas peak in 400-600 rfu; cut method collect log pencil exfoliated cells for DNA STR parting detection more than 12 loci in 10 cases(100%). Swabbing method collect cable joint cells DNA STR parting detected more than 12 loci 0 cases(0%), totally detected 17 loci, and atlas peak in 200-300 rfu; cut method collect cable joint cells DNA STR parting detected more than 12 loci in 5 cases(50%), detected 116 loci totally, and atlas peak in 200-800 rfu. In the actual cases swab method collect cable joint cells DNA STR parting detected more than 12 loci in 22 cases(66.70%); cut method collect cable joint cells DNA STR parting detected more than 12 loci in 32 cases(86.50%). In the actual cases swab method collect poison dart cells DNA STR parting detected more than 12 loci in 29 cases(39.73%); cut method collect poison dart cells DNA STR parting detected more than 12 loci in 80 cases(61.07%).Conclusion: The contact samples can get STR typing results, and the cutting method is batter than the swab method, especially in the cellophane tape group. Cutting-off method should be the priority for the collecting of exfoliative cells on contact samples.