CK: SNP typing used Snapshot or Agenia MassArray technology, also @appliedbio 3500 and 7500 #HIDS15
7:57am March 11th 2015 via Twitter Web Client
CK: Map of Yakutsk, two other areas. Bone (aDNA), teeth & hair too. Autosomal - kinships, Y-STRs for paternity, mt DNA for maternal #HID
CK: 150 graves, 145 remains, 130 of which DNA data ( mt DNA, Y-STRs, autosomal) as they were frozen in tundra. #HIDS15
CK: The Yakuts - an enigmatic ethnic group. Turkic-speaking, cattle-horse breeders, migrated in the 15th-19th century #HIDS15
7:56am March 11th 2015 via Twitter Web Client
Christine Keyser Institute of Legal Medicine, Strasbourg University, France: Discovery of 130 burials in Western Siberia #HIDS15
LR: It gives you the frequency 'what you want', acknowledges @lifetech support. #HIDS15
LR: Illustrates new features of YHRD database, likelihood ratio of paternity, other features. Showed progress from '00 to '14 #HIDS15
LR: YHRD - http://t.co/0SrDVWubYr running for 15y, showed geo distribution. Almost 100K Yfiler entries. Chart of Feb '15 Rel 49 #HIDS15
LR: Another paper illustrating stability of Y-chr 08 Fechner ref http://t.co/xkaMChF1E5 #HIDS15
LR: Showed population structure:Purps et al 2014 Nature Gen http://t.co/AmyEcvflxM from 23 loci #HIDS15
LR: Fast and slowly mutating Y-STRS: u=10^-9 to 10^-12, cp to u=10^-3, mutations start. Shows 1998 ref http://t.co/2AzxNTJLkZ #HIDS15
LR:Accused male w/ 6 brothers: differentiated by 45 markers, only 2 muts of 45 to discriminate 3 of the 6 first-deg relatives #HIDS15
LR: Of 66 cases sperm negative: 59% of these have single Y-STR profile. "Why Jack's point is important." #HIDS15
LR: Showed data for exoneration of a wrongly accused individual. Second full Y-STR match. 3rd: negative for sperm #HIDS15
7:55am March 11th 2015 via Twitter Web Client
LR: 95% of all profiles w/no match to YHRD. 21.6% cases w/o male DNA profile #HIDS15
LR: Study of types of evidence (retrospective), of 287 cases / 2077 stains, 2.8% no profile. 40% cases full single-source Y-STR #HIDS15
LR: Autosomal STR, Y-STR, 'the police expect it'. report both results, YHRD freq, mixture calculation #HIDS15
LR: UK Nat'l crime figures: Sexual assault cases up 17% '12-'13. They employ 2 kits/case. Chart of 'compulsory dual workflow' #HIDS15
Lutz Roewer Universitatsmedizin Berlin: The Golden Age of forensic Y-STR typing #HIDS15
JB: More loci - perhaps with MPS - could get complete male differentiation #HIDS15
JB: 'If they have evidence and they don't test Y-STR they aren't doing their job' #HIDS15
JB: Recommend labs to provide 'or arrange to provide' Y-STR typing services. Should collect data up to 10d post. #HIDS15
JB: 4d sample 27/27 alleles; 9d 0/27. Conclude: QF Trio has 'excellent correlation' between male quant and profile recovery #HIDS15
7:54am March 11th 2015 via Twitter Web Client
JB: Nested data improved detection rate. But can't be readily performed due to primer mix. Next: need to eliminate pre-amp. #HIDS15
JB: Used nested-PCR flanking Yfiler primers to inc sensitivity. Graph of # alleles (out of 17), about 1/4 in the 15-17 range #HIDS15
JB: Now onto 4d, 7d and 9d samples - straight to Yfiler Plus & QF Trio. Non-diff extracts only. Not a typical validation (caution) #HIDS
JB: (In other words, non-sperm fractions had no profile using Yfiler Plus.) #HIDS15
JB: His 4/7 lined up exactly to expected Yfiler Plus results based on sample, QF ratio and DI number. 2/7 were the 3d samples #HIDS15
JB: Used QF Trio, got parameters from samples, M:F ratios ranged from 1:10K to 1:0.06. 4/7 profiles obtained via Yfiler #HIDS15
JB: Down to 31g male DNA (17 alleles). 1:4000 mixtures detect fine. Did 1, 2 and 3d profiles. Differential (organic) extraction #HIDS15
7:53am March 11th 2015 via Twitter Web Client
JB: Describes new Yfiler kits (info http://t.co/rSofpjQQlv ) more loci, more discrimination, better chemistry. Map of loci #HIDS15
JB: Shares illus from Pater 2005 ref http://t.co/AS0hIGS3zw with a decision threshold for CV disease. FP/FN and TP/TN rates #HIDS15
JB: Quantifiler Trio: can calculate M/F ratio. Can proceed to Y-STR analysis if needed. Product page: https://t.co/bVsJTtkn0T #HIDS15
JB: Quotes SWGDAM Y-STR paper here (PDF) http://t.co/XkBwZknMYp qPCR 'an important tool' for M/F quantitation #HIDS15
JB: He's been working on it since. Now only 1/2 labs in the US use Y-STR's. Y-STRs only found in males, not as discriminatory #HIDS15
JB: Yet literature has 7-10 post-intercourse sperm can be detected. 1998: the question posed: can Y-chr data be used? #HIDS15
JB: Std. STR profiling late-reported intimate post-coital samples. 24-48h: success lessens rapidly. >72h not normally possible #HIDS15
JB: No suspect ID'd, >72h. Some victims don't report >3d after incident - perhaps due to incapacitation. Policy to not accept >3d #
7:52am March 11th 2015 via Twitter Web Client
JB: Also - to prevent innocent individuals from being charged. Why some rape evidence not submitted? Not requested, backlog #HIDS15
JB: 'Every victim deserves the right to determine the genetic profile of their assailant!' #HIDS15
JB: In US, 60% of sexual assaults never reported; now 1/5 have been victims of attempted or completed rape in their lifetime #HIDS15
Jack Ballantyne Nat'l Ctr Forensic Science FL Why Y chromosome biomarkers are an essential tool in sexual assault investigations #HIDS15
CH: Dedicated to all the field workers - to save more animals from absolute cruelty and real risk of extinction #HIDS15
7:50am March 11th 2015 via Twitter Web Client
CH:Moving toward int'l cases: Vietnamese man jailed only 15mos Jan '14 for having 8 pieces of horn in transit in Singapore #HIDS15
CH: Training - make collection of evidence part of crime scene training. Provides much better-quality samples. #HIDS15
CH: Have put together chain of collection kits in collaboration with SA Police; eRhODIS electronic data collection for field-use #HIDS15
CH: Ref assisted chromosome assembly chart shown, using domestic horse as a reference. #HIDS15
7:49am March 11th 2015 via Twitter Web Client
CH: Routine analysis - blood, used 24 STRs, improved markers under development. @appliedbio helping development for int'l use #HIDS15
CH: Middle of horn shown to be best for DNA. Can match blood ("Bluestar Forensic Latent blood reagent") from evidence #HIDS15
CH: Person who had $450K suspected of transport of horn - able to obtain two DNA matches, tied back to illegal poaching #HIDS15
