Development and Validation of the AmpFℓSTR^® MiniFiler^TM PCR Amplification Kit: A MiniSTR Multiplex for the Analysis of Degraded and/or PCR Inhibited DNA*

Abstract

DNA typing of degraded DNA samples can be a challenging task when using the current commercially available multiplex short tandem repeat (STR) analysis kits. However, the ability to type degraded DNA specimens improves by redesigning current STR marker amplicons such that smaller sized polymerase chain reaction (PCR) products are generated. In an effort to increase the amount of information derived from these types of DNA samples, the AmpF'STR Ò MiniFiler TM PCR Amplification Kit has been developed. The kit contains reagents for the amplification of eight miniSTRs which are the largest sized loci in the AmpF'STR Ò Identifiler Ò PCR Amplification Kit (D7S820, D13S317, D16S539, D21S11, D2S1338, D18S51, CSF1PO, and FGA). Five of these STR loci (D16S539, D21S11, D2S1338, D18S51, and FGA) also are some of the largest loci in the AmpF'STR Ò SGM Plus Ò kit. This informative nine-locus multiplex, which includes the gender-identification locus Amelogenin, has been validated according to the FBI ⁄ National Standards and SWGDAM guidelines. Our results demonstrate significant performance improvements in models of DNA degradation, PCR inhibition, and nonprobative samples when compared to the AmpF'STR Ò Identifiler Ò and SGM Plus Ò kits. These data support that the MiniFiler TM kit will increase the likelihood of obtaining additional STR information from forensic samples in situations in which standard STR chemistries fail to produce complete profiles.

Concordance study between the ParaDNA ® Intelligence Test, a Rapid DNA profiling assay, and a conventional STR typing kit (AmpFlSTR ® SGM Plus ® )

“…Concordance studies between STR typing kits are conducted during the developmental validation to confirm the validity of data produced by each with reference to others [7,8], in particular to detect the presence of mutations such as single nucleotide polymorphisms(SNPs)or deletions that might affect primer binding, thereby causing null alleles [9]. Concordance studies are typically conducted on a number (typically several hundred or more) of samples from individuals in a reference population or population subgroup using one profiling kit for which profiling data has been obtained using another product, thus establishing concordance between the profiles generated by the two products [4,10,11].…”

Development of two new Mini-STR multiplex assay for typing archival Bouin's fluid-fixed paraffin-embedded tissues

“…The forensic usefulness of Mini-STRs and the significant improvements in terms of number of loci amplified with MiniFiler TM kit on degraded DNA compared to Identifiler 1 kit, is widely demonstrated [2]. Thus, new Mini-STR PCR-multiplexes were designed in order to obtain PCR products with length less than 120 bp in size.…”

Forensic Genetics and Genotyping

“…old bones, hair shafts) and minute amounts of cells occasionally lead to the elimination of single or, in the worst case, all alleles (2). In this case STR typing can be improved by moving the PCR primers closer to the STR repeat region, which reduces sizes of product while retaining the same information (3,28,36,41). Thus, STR products reduced in lengths are marked as mini STR and if they are smaller than some of the fragmented DNA template molecules, genetic characterization of the sample may then be possible (28,36).…”

“…Gill et al described the acceptance of three new mini-STRs (D10S1248, D14S1434, D22S1045) into the European standard Interpol loci which now include 10 STR loci (42). Mulero et al described the conversion of eight STRs (D7S820, D13S317, D16S539, D21S11, D2S1338, D18S51, CSF1PO, and FGA) into miniSTRs (41). The amplicon range for mini-STRs is 71-250 bp in length.…”