Assessment of the stochastic threshold, back- and forward stutter filters and low template techniques for NGM

Forensic genetic SNP typing of low-template DNA and highly degraded DNA from crime case samples

“…The four allele drop-ins were reexamined, but it was not possible to deduce whether the drop-ins were caused by a contamination or unusual high background noise in the electropherograms. The low drop-in rate of the sensitized SNPforID assay is in sharp contrast to the sensitized STR assays, where the drop-in rate may be 100 times higher [10][11][12][13][14][15][16][17][18]. Allele drop-ins are very problematic, because they may lead to false inclusions as well as false exclusions.…”

Genotyping and interpretation of STR-DNA: Low-template, mixtures and database matches—Twenty years of research and development

“…The most common and pronounced stutter is one repeat unit shorter than 1234 the parental allelic peak (back stutter The stutter ratio is also affected by the size of the repeat unit, hence 1263 the tri-nucleotide repeat locus D22S1045 is expected to show higher stutter 1264 ratios than tetra-nucleotide repeat locus [154]. We are grateful to an anonymous referee who greatly improved the manuscript.…”

“…A risk analysis associated with choice of PrD 1196 to designate the threshold is provided by Gill et al [153] and demonstrated 1197 by Kirkham et al [147]. Alternative ways to estimate the stochastic threshold 1198 have been published: empirical cumulative distribution of peak heights from 1199single heterozygote peaks[154], peak height of the largest observed single Data generated from AB3500xl analyser. Plot of average peak height vs. natural logarithm of Hb (764 data-points), showing increased variance as the stochastic threshold (T = 634 RFU) is approached (vertical dotted line).…”

Forensic DNA Technological Advancements as an Emerging Perspective on Medico-Legal Autopsy: A Mini Review

“…The number of markers can be amplified simultaneously in the same aliquot with an optimized mix of primer pairs, but the reaction can be inefficient due to the presence of different inhibitor molecules. When amplifying a low level of sample DNA-with higher probability of mixed samples-an unequal, stochastic fluctuation can manifest, which may lead to a preferential, imbalanced presence of the allelic component, and the number of PCR cycles cannot be increased unlimitedly [17, [82][83][84].…”