Results of the 2018 Rapid DNA Maturity Assessment

Abstract

Three commercially available integrated rapid DNA instruments were tested as a part of a rapid DNA maturity assessment in July of 2018. The assessment was conducted with sets of blinded single-source reference samples provided to participants for testing on the individual rapid platforms within their laboratories. The data were returned to the National Institute of Standards and Technology (NIST) for review and analysis. Both FBI-defined automated review (Rapid DNA Analysis) and manual review (Modified Rapid DNA Analysis) of the datasets were conducted to assess the success of genotyping the 20 Combined DNA Index System (CODIS) core STR loci and full profiles generated by the instruments. Genotype results from the multiple platforms, participating laboratories, and STR typing chemistries were combined into a single analysis. The Rapid DNA Analysis resulted in a success rate of 80% for full profiles (85% for the 20 CODIS core loci) with automated analysis. Modified Rapid DNA Analysis resulted in a success rate of 90% for both the CODIS 20 core loci and full profiles (all attempted loci per chemistry). An analysis of the peak height ratios demonstrated that 95% of all heterozygous alleles were above 59% heterozygote balance. For base-pair sizing precision, the precision was below the standard 0.5 bp deviation for both the ANDE 6C System and the RapidHIT 200.

Keywords: ANDE 6C; FlexPlex; GlobalFiler; RapidHIT 200; RapidHIT ID; integrated device; rapid DNA.

Figure 1:

Genotyping success for Rapid DNA Analysis using the ANDE 6C System (n=5 instruments). Individual results are indicated by the circles and triangles for the CODIS 20 loci and full profiles, respectively. The box-plot to the right of each subset of data provides the overall mean of all data within each corresponding dataset(crosshatch) and median (line).The box within the boxplot represents the 5^th percentile at the lower end, and the 95^th percentile bounds at the upper end. The whiskers represent the upper and lower data points for individual instruments per dataset.

Figure 2:

Genotyping success for Modified Rapid DNA Analysis (n=12 instruments). Individual results are indicated by the circles and triangles for the CODIS 20 loci and full profiles, respectively. The box-plot to the right of each subset of data provides the overall mean of all data within each corresponding dataset(crosshatch) and median (line). The box within the boxplot represents the 5^th percentile at the lower end, and the 95^th percentile bounds at the upper end. The whiskers represent the upper and lower data points for individual instruments per dataset.

Figure 3:

Examples of the samples which were unable to be recovered. (a) Instrument Failure. (b) Partial Profile. (c) Single Locus Dropout.

Figure 4:

Observed discordance at Penta E with the ANDE 6C Rapid DNA Analysis. (a) ANDE 6C expert system genotype call (, 15.4). (b) Modified Rapid DNA Analysis of the ANDE .fsa file generated in GeneMapper IDX v1.5 (11,16). (c) Laboratory generated PowerPlex Fusion 6C profile at Penta E (11,16)

Figure 5:

Heterozygote Balance across three rapid DNA instruments. The line at 0.59 represents the heterozygote balance where 95 % of the heterozygous loci examined were above a peak height ratio of 59 %.

Figure 6:

Base-pair sizing precision for two of the three rapid DNA instruments. (a) ANDE 6C Precision. (b) RapidHIT 200 Precision. These two incorporate a ladder that is run in tandem with samples for each run.