Report of a european collaborative exercise comparing DNA typing results using a single locus VNTR probe

In the collaborative exercise GEDNAP IV one EDTA blood sample (2 ml) and 5 bloodstains (0.5 ml on cotton) were investigated and in GEDNAP V, a total of 8 bloodstains (0.5 ml on cotton), including 2 mixed bloodstains. DNA typing was carried out using the RFLP systems YNH24/Hinf I and MS43a/Hinf I and the PCR systems HLA DQ alpha, D1S80, ApoB and YNZ22. In both exercises approximately 20 laboratories obtained results using the RFLP systems. Of the PCR systems, D1S80 was the most commonly used (14 labs in GEDNAP IV; 18 labs in GEDNAP V). The interlaboratory standard deviation for YNH24 in both exercises was approx. 0.6%, for MS43a 0.7-2.2% (GEDNAP IV) and 0.4-1.4% (GEDNAP V), depending on the fragment size. The fragment size calculation performed in each laboratory yielded a standard deviation twice that obtained when the fragment size calculation was performed centrally (IfR, Münster). In GEDNAP III, a system-specific corridor was developed to define the limits of deviation; this was modified for the present study by combining the fragment size ranges of YNH24 and MS43a. In both studies a subgroup of laboratories was involved in preliminary exercises using three PCR VNTRs and the system HLA DQ alpha. Owing to the substantial variation in experience of the participating laboratories with PCR typing the results obtained in these two studies do not fulfil the basic quality criteria of the GEDNAP studies.

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“…lb). These and the remaining statistical figures are also very similar to those in the EDNAP studies (Schneider et al 1991, Gill et al 1992.…”

Section: Gednap Vsupporting

confidence: 82%

GEDNAP IV and V. The 4th and 5th stain blind trials using DNA technology

et al. 1995

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“…3d). More work is needed to establish an effective comparison of allelic data between laboratories (similar to SLP and EDNAP -see Schneider et al 1991) for some genetic markers and sample sizes should be increased before meaningful comparisons can be made.…”

Section: Comparison Of Different Population Studiesmentioning

confidence: 98%

Population genetics and forensic efficiency data of 4 AMPFLP's

et al. 1992

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Family studies were carried out in a population sample from north west Germany using 4 amplifiable VNTR polymorphic systems D1S80 (MCT118), ApoB, D17S30 (YNZ22) and COL2A1. Separation was carried out in polyacrylamide gels and visualised using silver staining. In family studies (n = 30) no evidence of new mutations was found. The population study of unrelated individuals (mothers and putative fathers) showed that all 4 systems were highly polymorphic and similar to other population studies. The combined exclusion chance was calculated to be approximately 99% and the combined discrimination index 1.5.10(-4). The Hardy-Weinberg equilibrium was checked by forming groups of alleles and no significant deviations could be found in all systems.

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“…These data (as those of Section 2.2a) were generated in our laboratoryusing the protocol described in [; 'I with onlyminor changes ( terlaboratory variance: Data produced from a collaborative experiment between several European laboratories were considered. A detailed account of this experiment, together with comprehensive statistics referring to the interlaboratoryvariance,is to be found in [7].Values in kb, produced at the Home Office Central Research Establishment, Aldermaston, by charge-coupled device (CCD) video-camera processing of autoradiograms, were made available to all participating laboratories. Fifteen bands pertaining to different SLPs, analyzed by five different laboratories are here taken into account, selected with the only criterion that each laboratory contribute almost the same number of measurements (5-12 measurements per band) and that as many molecular weight sizes as possible be in the range from 1 to 5 kb.…”

Section: Selection Of Datamentioning

confidence: 99%

“…Genomic DNA was extracted, enzymatically restricted (~i~f l , promega, # ~6 2 0~) and processed according to a standard protocol of SBA [7]. Gels (0.7% w/v agarose, Sea-FMC, #/ 50074) were electrophoresed to meet Optima' resolution in the range from 1 to 5 kb,where most sLp fragments of our single-locus probes were expected.…”

Section: Experimental Modelmentioning

confidence: 99%

Errors in sizing bands of hypervariable DNA profiles on autoradiograms: Are they Gaussian?

et al. 1992

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The accuracy of procedures for sizing hypervariable restriction fragments by Southern blot analysis (SBA) has been tested under three different experimental conditions: (i) intrablot serial analyses: three heterozygous DNA profiles were tested 14 times each in the same gel electrophoresis; (ii) intralaboratory analyses: we replicated three profiles (six autoradiographic bands) in over 100 SBA experiments; (iii) interlaboratory analyses: 15 serial measurements produced in a recent collaborative study (Forensic Sci. Int. 1991, 49, 1-15) were taken into account. In these three cases, a typical U-shaped correlation curve between molecular size and coefficient of variation was found. We explain decrease of accuracy at both extremities of the gels in terms of: (i) enlarged shapes of bands and mean electrophoretic resolution at the cathode; (ii) diffusion and blurring of bands at the anodal edge. The three populations of data were subjected to a chi 2 test and to the Kolmogorov-Smirnov test in order to verify their compliance with normal distribution. Twenty-three out of 27 tests indicated no significant deviation from the assumption of Gaussian distribution. We recommend the adoption of tests for normality to validate the use of symmetric confidence intervals for calculating gene frequencies and asserting a match between adjacent bands.

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Report of a european collaborative exercise comparing DNA typing results using a single locus VNTR probe

Cited by 43 publications

References 9 publications

GEDNAP IV and V. The 4th and 5th stain blind trials using DNA technology

GEDNAP IV and V. The 4th and 5th stain blind trials using DNA technology

Population genetics and forensic efficiency data of 4 AMPFLP's

Errors in sizing bands of hypervariable DNA profiles on autoradiograms: Are they Gaussian?

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