Forensic Body Fluid Identification by Analysis of Multiple RNA Markers Using NanoString Technology

RNA analysis has become a reliable method of body fluid identification for forensic use. Previously, we developed a combination of four multiplex quantitative PCR (qRT-PCR) probes to discriminate four different body fluids (blood, semen, saliva, and vaginal secretion). While those makers successfully identified most body fluid samples, there were some cases of false positive and negative identification. To improve the accuracy of the identification further, we tried to use multiple markers per body fluid and adopted the NanoString nCounter system instead of a multiplex qRT-PCR system. After measuring tens of RNA markers, we evaluated the accuracy of each marker for body fluid identification. For body fluids, such as blood and semen, each body fluid-specific marker was accurate enough for perfect identification. However, for saliva and vaginal secretion, no single marker was perfect. Thus, we designed a logistic regression model with multiple markers for saliva and vaginal secretion and achieved almost perfect identification. In conclusion, the NanoString nCounter is an efficient platform for measuring multiple RNA markers per body fluid and will be useful for forensic RNA analysis.

Comparison of parentage testing results from several institutes in Korea / 대한법의학회지

Collaborative work using same samples for the parentage testing, which was intended to see the status and the quality of several DNA typing laboratories in Korea, was described. Samples were consisted of two sets, one was a trio case and the other was a deficient case with two children. Samples were sent to six laboratories, among which five submitted the result. Each laboratory had used different number and set of STR loci using 14 - 23 loci, and total 33 different loci were used. Only one VNTR locus, D1S80 was included and all the remaining were STR loci. The loci included in the commercial kits were used more frequently. One laboratory had used Korean-made commercial kits. All the laboratories gave the same results about the parentage, although results for one locus were not the same through different laboratories. There existed minor difference in the PI calculation, especially in the statistical parameters such as allelic frequences, which might gave confusion to users of the results who were not familiar with the test. Necessity about the standardization and profiling data were discussed.

Comparison of STR Typing Results from Several Centers for the Same Samples: Steps to Standardization for STR Typing / 대한법의학회지

This paper described a collaborative exercise intended to see what kinds of short tandem repeat (STR) loci are used in different DNA typing laboratories in Korea and to compare their results for the demonstration whether uniformity of DNA profiling results from different laboratory could be achieved in Korea. Laboratories were asked to test five tissue DNAs using methods routinely used in each laboratory and to report the results to the coordinating laboratory. The exercise demonstrated that each laboratory was using different STR loci for the typing with different STR numbers, 2 VNTRs, 36 STRs and amelogenin in total, and the direct comparison of the results from all the laboratory for the 18 loci could not be done as only one laboratory submitted typing results. Among 21 loci for which several laboratories submitted typing results, results for 14 loci were the same and results for the other 7 loci were different depending on the participating laboratory. D1S80, F13A01, D16S539, D21S11, D18S51, D3S1744 were the loci with different typing results. Even in the cases where commercial kits were used, the results were not the same depending on the machines used, that is the capillary electrophoresis or the gel based electrophoresis. The reason for the different results, points about the standardization of the methods and the profiling data were described.

Comparison of STR Typing Results from Several Centers for the Same Samples: Steps to Standardization for STR Typing / 대한법의학회지

This paper described a collaborative exercise intended to see what kinds of short tandem repeat (STR) loci are used in different DNA typing laboratories in Korea and to compare their results for the demonstration whether uniformity of DNA profiling results from different laboratory could be achieved in Korea. Laboratories were asked to test five tissue DNAs using methods routinely used in each laboratory and to report the results to the coordinating laboratory. The exercise demonstrated that each laboratory was using different STR loci for the typing with different STR numbers, 2 VNTRs, 36 STRs and amelogenin in total, and the direct comparison of the results from all the laboratory for the 18 loci could not be done as only one laboratory submitted typing results. Among 21 loci for which several laboratories submitted typing results, results for 14 loci were the same and results for the other 7 loci were different depending on the participating laboratory. D1S80, F13A01, D16S539, D21S11, D18S51, D3S1744 were the loci with different typing results. Even in the cases where commercial kits were used, the results were not the same depending on the machines used, that is the capillary electrophoresis or the gel based electrophoresis. The reason for the different results, points about the standardization of the methods and the profiling data were described.