Validation Information to Aid Forensic DNA Laboratories

[Presentation at Promega 2004 meeting] [Promega 2004 meeting publication] [Questionnaire used]

President's DNA Initiative Validation Workshop Materials for workshop held at NFSTC August 24-26, 2005

Validation Workshop (208 slides) presented for Applied Biosystems' HID University/Future Trends in Forensic DNA Technology in Albany, NY, May 10, 2006

To provide information or suggest improvements to this section of STRBase, please contact John Butler <john.butler@nist.gov>.

[Explanation of Validation] [Standards/Guidelines] [Validation Summary Sheets] [Internal Validation Studies] [Helpful Information] [Literature Summary]

Explanation of Validation

Validation refers to the process of demonstrating that a laboratory procedure is robust, reliable, and reproducible in the hands of the personnel performing the test in that laboratory.  A robust method is one in which successful results are obtained a high percentage of the time and few, if any, samples need to be repeated.  A reliable method refers to one in which the obtained results are accurate and correctly reflect the sample being tested.  A reproducible method means that the same or very similar results are obtained each time a sample is tested.  All three types of methods are important for techniques performed in forensic laboratories.

There are generally considered to be two stages to validation: developmental validation and internal validation.  Developmental validation involves the testing of new STR loci or STR kits, new primer sets, and new technologies for detecting STR alleles.  Internal validation, on the other hand, involves verifying that established procedures examined previously under the scrutiny of developmental validation (often by another laboratory) will work effectively in one’s own laboratory.  Developmental validation is typically performed by commercial STR kit manufacturers and large labs, such as the FBI Laboratory, while internal validation is the primary form of validation performed in smaller local and state forensic DNA laboratories.

Each forensic laboratory develops or adopts standard operating protocols (SOPs) that give a detailed listing of all the materials required to perform an assay as well as the exact steps required to successfully complete the experiment.  In addition, SOPs list critical aspects of the assay that must be monitored carefully.  SOPs are followed exactly when performing forensic DNA casework.

-Butler, J.M. (2001) Forensic DNA Typing: Biology and Technology Behind STR Markers, San Diego: Elsevier Academic Press, Chapter 14 "Laboratory Validation", pp. 205-222

The steps involved in bringing a procedure (assay, instrument, or software) “on-line” in a forensic lab setting typically include (1) installation of the instrumentation or software and purchase of assay reagents, (2) learning about the technique and how to perform it properly, (3) validation of the analytical procedure to define its range and reliability, (4) creation of the standard operating procedures with interpretation guidelines based on the validation studies, (5) training of other personnel on the technique, and (6) each trained analysts passing a qualification test for initial use in forensic casework. After a procedure has been successfully been implemented into use with forensic casework, proficiency tests are performed on a regular basis to demonstrate successful application of the technique over time by qualified analysts.

Standards and Guidelines Regarding Validation

Within the United States, the DNA Advisory Board (DAB) Standards govern forensic DNA analysis both for casework and database applications. Section 8 of the DAB standards speak specifically to the topic of validation but only in broad terms. Rather than providing specific recommended numbers for various studies, the focus of the DAB standards is on “appropriately documenting” developmental and internal validation along with material modifications.

The Revised SWGDAM Validation Guidelines were published in Forensic Science Communications in July 2004: http://www.fbi.gov/hq/lab/fsc/backissu/july2004/standards/2004_03_standards02.htm. This document states that internal validation studies should encompass a total of at least 50 samples (some studies may not be necessary due to the method itself)

Validation Summary Sheets

We are initiating an effort to catalog and summarize validation studies that have been published in the literature. The purpose of this effort is to provide details on studies conducted, a description of samples tested, and the number of samples run as part of the study in order to aid current and future validation efforts by forensic DNA laboratories. These validation summary sheets will aid the community in meeting SWGDAM Revised Validation Guideline 1.2.2.1 that “internal validation studies must be sufficiently documented and summarized.”

 Below is listed a compilation of references to various validation studies conducted using commercial STR kits, in-house assays, instrumentation, and software in human identity testing applications. A full reference bibliography is listed at the bottom of this page.  Click on the hyperlink to access a specific Validation Summary Sheet (note that not all validation summaries have been completed yet).

Kit, Assay, or Instrument	Reference
PowerPlex Y	Krenke et al. (2005)
Profiler Plus	Frank et al. (2001), LaFountain et al. (2001), Tomsey et al. (2001), Holt et al. (2002), Fregeau et al. (2003), Buse et al. (2003), Wallin et al. (2002), Pawlowski et al. (2000), Moretti et al. (2001)
COfiler	LaFountain et al. (2001), Tomsey et al. (2001), Moretti et al. (2001), Holt et al. (2002), Buse et al. (2003), Wallin et al. (2002)
SGM Plus	Cotton et al. (2000)
AmpFlSTR Blue	Wallin et al. (1998)
AmpFlSTR Green I	Holt et al. (2002)
Profiler	Holt et al. (2002)
Profiler Plus ID	Leibelt et al. (2003)
Identifiler	Collins et al. (2004)
SEfiler	Coticone et al. (2004)
PowerPlex 1.1	Micka et al. (1999), Tomsey et al. (2001), Greenspoon et al. (2001)
PowerPlex 1.1 + D16 primer	Nelson et al. (2002)
PowerPlex 2.1	Tomsey et al. (2001), Levedakou et al. (2002)
PowerPlex 16	Krenke et al. (2002), Tomsey et al. (2001)
PowerPlex 16 BIO	Greenspoon et al. (2004)
Y-PLEX 6	Sinha et al. (2003a)
Y-PLEX 5	Sinha et al. (2003b)
Y-PLEX 12	Shewale et al. (2004)
genRES MPX-2	Junge et al. (2003)
Reduced volume PCR for Profiler Plus STR kit	Gaines et al. (2002), Fregeau et al. (2003)
SGM	Sparkes et al. (1996), Sparkes et al. (1996), Kimpton et al. (1996)
TH01, VWA, F13A1, FES	Lygo et al. (1994), Clayton et al. (1995), Andersen et al. (1996)
CTT	Budowle et al. (1997)
D3S1358, D8S1179, D18S51	Potter (2003)
TH01, VWA, F13A1, FES, LPL	Pestoni et al. (1995)
STR sets	Crouse and Schumm (1995), Micka et al. (1996)
TH01	Van Oorschot et al. (1996), Wiegand et al. (1993)
D12S391	Junge et al. (1999)
Amelogenin	LaFountain et al. (1998)
Y-STR 4plex	Prinz et al. (2001)
Y-STR 10plex	Johnson et al. (2003)
19-locus Y-STR system	Daniels et al. (2004)
ABI 377	Frazier et al. (1996), Fregeau et al. (1999)
ABI 310	Lazaruk et al. (1998), Isenberg et al. (1998), Moretti et al. (2001)
ABI 3100	Sgueglia et al. (2003), Koumi et al. (2004)
ABI 3700	Gill et al. (2001), Koumi et al. (2004)
MegaBACE	Koumi et al. (2004)
DNA quant (RT-PCR Alu)	Nicklas and Buel (2003)
DNA quant (RT-PCR CSF)	Richard et al. (2003)
DNA quant (AluQuant)	Mandrekar et al. (2001)
BodeQuant	Fox et al. (2003)
Quantifiler	Applied Biosystems (2003)
Biomek 2000 with DNA IQ	Greenspoon et al. (2004)
mtDNA sequencing	Wilson et al. (1995), Holland and Parsons (1999)
mtDNA minisequencing	Morley et al. (1999)
TrueAllele software	Kadash et al. (2004)
CompareCalls software	Ryan et al. (2004)
21-SNP multiplex	Dixon et al. (2005)

We invite updates to this table. Please contact John Butler <john.butler@nist.gov> if you would like to add a summary of your laboratory's validation studies with a particular forensic DNA test, instrument, or software program. Please submit information in a standard format summarizing the studies conducted, a description of samples run, and the number of samples examined using this downloadable Excel file [click here].

Internal Validation Studies Conducted in Individual Laboratories (not published in the literature)

Helpful Information with STR Kit Validation (with SWGDAM revised validation guideline sections indicated)

Validation Workshop held at NFSTC August 24-26, 2005

Information will be included here to help with individual lab validation studies and is based on a community-wide effort either through literature extraction or direct contribution. If you have something that you feel would be helpful to others regarding a particular aspect of validation, please contact John Butler <john.butler@nist.gov>. Information will be posted along with the source and contact information if someone wants to learn more.

 The information below is organized following the SWGDAM Revised Validation Guidelines with the numbers in parentheses referring to the various sections of the document.

 Developmental Validation

Characterization of Genetics Markers (2.1): STRBase STR Fact Sheets, Forensic SNP information

Inheritance (2.1.1):

Mapping (2.1.2):

Detection (2.1.3):

Polymorphism (2.1.4):

Species Specificity (2.2):

Sensitivity Studies (2.3):

Stability Studies (2.4):

Reproducibility (2.5):

Case-type Samples (2.6):

Population Studies (2.7):

Mixture Studies (2.8):

Precision and Accuracy (2.9):

PCR-Based Procedures (2.10):

Internal Validation

Known and Nonprobative Evidence Samples (3.1):

Reproducibility and Precision (3.2):

Match Criteria (3.3):

Sensitivity and Stochastic Studies (3.4):

Mixture Studies (3.5):

Contamination (3.6):

Qualifying Test (3.7):

Material Modification

Performance Check of Established Procedures

Validation Literature References

Andersen JF, Greenhalgh MJ, Butler HR, Kilpatrick SR, Piercy RC, Way KA, Myhill HS, Wright JC, Hallett R, Parkin BH. Further validation of a multiplex STR system for use in routine forensic identity testing. Forensic Sci Int 1996; 78:47-64.

Applied Biosystems. Quantifiler Human DNA Quantification Kit User's Manual. Applied Biosystems, Foster City, California, 2003.

Budowle B, Moretti TR, Keys KM, Koons BW, Smerick JB. Validation studies of the CTT STR multiplex system. J Forensic Sci 1997; 42(4):701-707.

Buse EL, Putinier JC, Hong MM, Yap AE, Hartmann JM. Performance evaluation of two multiplexes used in fluorescent short tandem repeat DNA analysis. J Forensic Sci 2003; 48(2):348-357.

Butler JM. Forensic DNA Typing: Biology and Technology behind STR Markers. London: Academic Press, 2001. Chapter 14 “Laboratory Validation” pp. 205-222.

Clayton TM, Whitaker JP, Fisher DL, Lee DA, Holland MM, Weedn VW, Maguire CN, DiZinno JA, Kimpton CP, Gill P. Further validation of a quadruplex STR DNA typing system: a collaborative effort to identify victims of a mass disaster. Forensic Sci Int 1995; 76:17-25

Collins PJ, Hennessy LK, Leibelt CS, Roby RK, Reeder DJ, Foxall PA (2004) Developmental validation of a single-tube amplification of the 13 CODIS STR loci, D2S1338, D19S433, and amelogenin: the AmpFlSTR Identifiler PCR amplification kit. J. Forensic Sci. 49(6):1265-1277.

Coticone SR, Oldroyd N, Philips H, Foxall P. Development of the AmpFISTR SEfiler PCR amplification kit: a new multiplex containing the highly discriminating ACTBP2 (SE33) locus. Int J Legal Med 2004; 118(4):224-234.

Cotton EA, Allsop RF, Guest JL, Frazier RR, Koumi P, Callow IP, Seager A, Sparkes RL. Validation of the AMPFlSTR((R)) SGM plus system for use in forensic casework. Forensic Sci Int 2000; 112(2-3):151-161.

Crouse C, Schumm JW. Investigation of species specificity using nine PCR-based human STR systems. J Forensic Sci 1995; 40(6):952-956.

Crouse CA. Implementation of forensic DNA analysis on casework evidence at the Palm Beach County Sheriff’s Office Crime Laboratory: historical perspective. Croat Med J 2001;42(3):247-251.

Daniels DL, Hall AM, Ballantyne J. SWGDAM developmental validation of a 19-locus Y-STR system for forensic casework. J Forensic Sci 2004; 49(4):668-683.

Dixon, L.A., Murray, C.M., Archer, E.J., Dobbins, A.E., Koumi, P., Gill P. (2005) Validation of a 21-locus autosomal SNP multiplex for forensic identification purposes. Forensic Sci Int. 154: 62–77

Federal Bureau of Investigation. Quality assurance standards for forensic DNA testing laboratories, Forensic Science Communications [Online]. (July 2000A). Available : http://www.fbi.gov/hq/lab/fsc/backissu/july2000/codispre.htm.

Federal Bureau of Investigation. Quality assurance standards for convicted offender DNA databasing laboratories, Forensic Science Communications [Online]. (July 2000B). Available: http://www.fbi.gov/hq/lab/fsc/backissu/july2000/codispre.htm.

Food and Drug Administration. General principles of software validation; final guidance for industry and FDA staff. Document issued January 11, 2002. Available: http://www.fda.gov/cdrh/comp/guidance/938.pdf.

Fox JC, Cave CA, Schumm JW. Development, characterization, and validation of a sensitive primate-specific quantification assay for forensic analysis. Biotechniques 2003; 34(2):314-8, 320, 322.

Frank WE, Llewellyn BE, Fish PA, Riech AK, Marcacci TL, Gandor DW, Parker D, Carter RR, Thibault SM. Validation of the AmpFlSTR Profiler Plus PCR amplification kit for use in forensic casework. J Forensic Sci 2001; 46(3):642-646.

Frazier RR, Millican ES, Watson SK, Oldroyd NJ, Sparkes RL, Taylor KM, Panchal S, Bark L, Kimpton CP, Gill PD. Validation of the Applied Biosystems Prism^TM 377 automated sequencer for forensic short tandem repeat analysis. Electrophoresis 1996; 17(10):1550-1552.

Fregeau CJ, Bowen KL, Fourney RM. Validation of highly polymorphic fluorescent multiplex short tandem repeat systems using two generations of DNA sequencers. J Forensic Sci 1999; 44(1):133-166.

Fregeau CJ, Bowen KL, Leclair B, Trudel I, Bishop L, Fourney RM. AmpFlSTR Profiler Plus short tandem repeat DNA analysis of casework samples, mixture samples, and nonhuman DNA samples amplified under reduced PCR volume conditions (25 microL). J Forensic Sci 2003; 48(5):1014-1034.

Gaines ML, Wojtkiewicz PW, Valentine JA, Brown CL. Reduced volume PCR amplification reactions using the AmpFlSTR Profiler Plus kit. J Forensic Sci 2002; 47(6):1224-1237.

Gill P, Koumi P, Allen H. Sizing short tandem repeat alleles in capillary array gel electrophoresis instruments. Electrophoresis 2001;22:2670-2678.

Greenspoon SA, Lytle PJ, Turek SA, Rolands JM, Scarpetta MA, Carr CD. Validation of the PowerPlex 1.1 loci for use in human identification. J Forensic Sci 2000; 45(3):677-683.

Greenspoon SA, Ban JD, Pablo L, Crouse CA, Kist FG, Tomsey CS, Glessner AL, Mihalacki LR, Long TM, Heidebrecht BJ, Braunstein CA, Freeman DA, Soberalski C, Nathan B, Amin AS, Douglas EK, Schumm JW. Validation and implementation of the PowerPlex 16 BIO System STR multiplex for forensic casework. J Forensic Sci 2004; 49(1):71-80.

Greenspoon SA, Ban JD, Sykes K, Ballard EJ, Edler SS, Baisden M, Covington BL. Application of the BioMek 2000 Laboratory Automation Workstation and the DNA IQ System to the extraction of forensic casework samples. J Forensic Sci 2004; 49(1):29-39.

Holland MM, Parsons TJ. Mitochondrial DNA sequence analysis - validation and use for forensic casework. Forensic Sci Rev 1999; 11(1):22-50.

Holt CL, Buoncristiani M, Wallin JM, Nguyen T, Lazaruk KD, Walsh PS. TWGDAM validation of AmpFlSTR PCR amplification kits for forensic DNA casework. J Forensic Sci 2002; 47(1):66-96.

Isenberg AR, Allen RO, Keys KM, Smerick JB, Budowle B, McCord BR. Analysis of two multiplexed short tandem repeat systems using capillary electrophoresis with multiwavelength florescence detection. Electrophoresis 1998;19:94-100.

Johnson CL, Warren JH, Giles RC, Staub RW. Validation and uses of a Y-chromosome STR 10-plex for forensic and paternity laboratories. J Forensic Sci 2003; 48(6):1260-1268.

Junge A, Madea B. Validation studies and characterization of variant alleles at the short tandem repeat locus D12S391. Int J Legal Med 1999; 112(1):67-69.

Junge A, Lederer T, Braunschweiger G, Madea B. Validation of the multiplex kit genRESMPX-2 for forensic casework analysis. Int J Legal Med 2003; 117(6):317-325.

Kadash K, Kozlowski BE, Biega LA, Duceman BW. Validation study of the TrueAllele automated data review system. J Forensic Sci 2004; 49(4):660-667.

Kimpton CP, Fisher D, Watson S, Adams M, Urquhart A, Lygo J, Gill P. Evaluation of an automated DNA profiling system employing multiplex amplification of four tetrameric STR loci. Int J Leg Med 1994; 106:302-311.

Kimpton CP, Oldroyd NJ, Watson SK, Frazier RR, Johnson PE, Millican ES, Urquhart A, Sparkes BL, Gill P. Validation of highly discriminating multiplex short tandem repeat amplification systems for individual identification. Electrophoresis 1996; 17(8):1283-1293.

Koumi P, Green HE, Hartley S, Jordan D, Lahec S, Livett RJ, Tsang KW, Ward DM. Evaluation and validation of the ABI 3700, ABI 3100, and the MegaBACE 1000 capillary array electrophoresis instruments for use with short tandem repeat microsatellite typing in a forensic environment. Electrophoresis 2004; 25(14):2227-2241.

Krenke BE, Tereba A, Anderson SJ, Buel E, Culhane S, Finis CJ, Tomsey CS, Zachetti JM, Masibay A, Rabbach DR, Amiott EA, Sprecher CJ. Validation of a 16-locus fluorescent multiplex system. J Forensic Sci 2002; 47(4):773-785.

Krenke BE, Viculis L, Richard ML, Prinz M, Milne SC, Ladd C, Gross AM, Gornall T, Frappier JRH, Eisenberg AJ, Barna C, Aranda XG, Adamowicz, Budowle B. Validation of a male-specific, 12-locus fluorescent short tandem repeat (STR) multiplex. Forensic Sci Int 2005; 148:1-14.

LaFountain MJ, Schwartz MB, Svete PA, Walkinshaw MA, Buel E. TWGDAM validation of the AmpFlSTR Profiler Plus and AmpFlSTR COfiler STR multiplex systems using capillary electrophoresis. J Forensic Sci 2001; 46(5):1191-1198.

LaFountain M, Schwartz M, Cormier J, Buel E. Validation of capillary electrophoresis for analysis of the X-Y homologous amelogenin gene. J Forensic Sci 1998; 43(6):1188-1194.

Lazaruk K, Walsh PS, Oaks F, Gilbert D, Rosenblum BB, Menchen S, Scheibler D, Wenz HM, Holt C, Wallin J. Genotyping of forensic short tandem repeat (STR) systems based on sizing precision in a capillary electrophoresis instrument. Electrophoresis 1998;19(1):86-93.

Leibelt C, Budowle B, Collins P, Daoudi Y, Moretti T, Nunn G, Reeder D, Roby R. Identification of a D8S1179 primer binding site mutation and the validation of a primer designed to recover null alleles. Forensic Sci Int 2003; 133(3):220-227.

Levedakou EN, Freeman DA, Budzynski MJ, Early BE, Damaso RC, Pollard AM, Townley AJ, Gombos JL, Lewis JL, Kist FG, Hockensmith ME, Terwilliger ML, Amiott E, McElfresh KC, Schumm JW, Ulery SR, Konotop F, Sessa TL, Sailus JS, Crouse CA, Tomsey CS, Ban JD, Nelson MS. Characterization and validation studies of powerPlex 2.1, a nine-locus short tandem repeat (STR) multiplex system and penta D monoplex. J Forensic Sci 2002; 47(4):757-772.

Lygo JE, Johnson PE, Holdaway DJ, Woodroffe S, Whitaker JP, Clayton TM, Kimpton CP, Gill P. The validation of short tandem repeat (STR) loci for use in forensic casework. Int J Legal Med 1994; 107(2):77-89.

Mandrekar MN, Erickson AM, Kopp K, Krenke BE, Mandrekar PV, Nelson R, Peterson K, Shultz J, Tereba A, Westphal N. Development of a human DNA quantitation system. Croat Med J 2001; 42(3):336-339.

Micka KA, Sprecher CJ, Lins AM, Comey CT, Koons BW, Crouse C, Endean D, Pirelli K, Lee SB, Duda N, Ma M, Schumm JW. Validation of multiplex polymorphic STR amplification sets developed for personal identification applications. J Forensic Sci 1996; 41(4):582-590.

Micka KA, Amiott EA, Hockenberry TL, Sprecher CJ, Lins AM, Rabbach DR, Taylor JA, Bacher JW, Glidewell DE, Gibson SD, Crouse CA, Schumm JW. TWGDAM validation of a nine-locus and a four-locus fluorescent STR multiplex system. J Forensic Sci 1999; 44(6):1243-1257.

Moretti TR, Baumstark AL, Defenbaugh DA, Keys KM, Brown AL, Budowle B. Validation of STR typing by capillary electrophoresis. J Forensic Sci 2001; 46(3):661-676.

Moretti TR, Baumstark AL, Defenbaugh DA, Keys KM, Smerick JB, Budowle B. Validation of short tandem repeats (STRs) for forensic usage: performance testing of fluorescent multiplex STR systems and analysis of authentic and simulated forensic samples. J Forensic Sci 2001; 46(3):647-660.

Morley JM, Bark JE, Evans CE, Perry JG, Hewitt CA, Tully G. Validation of mitochondrial DNA minisequencing for forensic casework. Int J Legal Med 1999; 112(4):241-248.

Nelson MS, Levedakou EN, Matthews JR, Early BE, Freeman DA, Kuhn CA, Sprecher CJ, Amin AS, McElfresh KC, Schumm JW. Detection of a primer-binding site polymorphism for the STR locus D16S539 using the Powerplex 1.1 system and validation of a degenerate primer to correct for the polymorphism. J Forensic Sci 2002; 47(2):345-349.

Nicklas JA, Buel E. Development of an Alu-based, real-time PCR method for quantitation of human DNA in forensic samples. J Forensic Sci 2003;48(5):936-944.

Pawlowski R, Maciejewska A. Forensic validation of a multiplex containing nine STRs--population genetics in northern Poland.  Int J Legal Med 2000; 114(1-2):45-49.

Pestoni C, Lareu MV, Rodriguez MS, Munoz I, Barros F, Carracedo A. The use of the STRs HUMTH01, HUMVWA31/A, HUMF13A1, HUMFES/FPS, HUMLPL in forensic application: validation studies and population data for Galicia (NW Spain). Int J Legal Med 1995; 107(6):283-290.

Potter T. Co-amplification of ENFSI-loci D3S1358, D8S1179 and D18S51: validation of new primer sequences and allelic distribution among 2874 individuals. Forensic Sci Int 2003; 138(1-3):104-110.

Prinz M, Ishii A, Coleman A, Baum HJ, Shaler RC. Validation and casework application of a Y chromosome specific STR multiplex. Forensic Sci Int 2001; 120(3):177-188.

Richard ML, Frappier RH, Newman JC. Developmental validation of a real-time quantitative PCR assay for automated quantification of human DNA. J Forensic Sci 2003; 48(5):1041-1046.

Ryan JH, Barrus JK, Budowle B, Shannon CM, Thompson VW, Ward BE. The application of an automated allele concordance analysis system (CompareCalls) to ensure the accuracy of single-source STR DNA profiles. J Forensic Sci 2004; 49(3):492-499.

Sgueglia JB, Geiger S, Davis J. Precision studies using the ABI prism 3100 genetic analyzer for forensic DNA analysis. Anal Bioanal Chem 2003; 376(8):1247-1254.

Shewale JG, Nasir H, Schneida E, Gross AM, Budowle B, Sinha SK. Y-chromosome STR system, Y-PLEX 12, for forensic casework: development and validation. J Forensic Sci 2004;49(6):1278-1290.

Sinha SK, Budowle B, Arcot SS, Richey SL, Chakrabor R, Jones MD, Wojtkiewicz PW, Schoenbauer DA, Gross AM, Sinha SK, Shewale JG. Development and validation of a multiplexed Y-chromosome STR genotyping system, Y-PLEX 6, for forensic casework. J Forensic Sci 2003; 48(1):93-103.

Sinha SK, Nasir H, Gross AM, Budowle B, Shewale JG. Development and validation of the Y-PLEX 5, a Y-chromosome STR genotyping system, for forensic casework. J Forensic Sci 2003; 48(5):985-1000.

Sparkes R, Kimpton CP, Watson S, Oldroyd NJ, Clayton TM, Barnett L, Arnold J, Thompson C, Hale R, Chapman J, Urquhart A, Gill P. The validation of a 7-locus multiplex STR test for use in forensic casework. (I). Mixtures, ageing, degradation and species studies.  Int J Legal Med 1996; 109(4):186-194.

Sparkes R, Kimpton C, Gilbard S, Carne P, Andersen J, Oldroyd N, Thomas D, Urquhart A, Gill P. The validation of a 7-locus multiplex STR test for use in forensic casework. (II), Artefacts, casework studies and success rates. Int J Legal Med 1996; 109(4):195-204.

Szibor R, Edelmann J, Hering S, Plate I, Wittig H, Roewer L, Wiegand P, Cali F, Romano V, Michael M. Cell line DNA typing in forensic genetics--the necessity of reliable standards. Forensic Sci Int 2003; 138(1-3):37-43.

Tomsey CS, Kurtz M, Kist F, Hockensmith M, Call P. Comparison of PowerPlex 16, PowerPlex1.1/2.1, and ABI AmpFISTR Profiler Plus/COfiler for forensic use. Croat Med J 2001; 42(3):239-243.

van Oorschot RA, Gutowski SJ, Robinson SL, Hedley JA, Andrew IR. HUMTH01 validation studies: effect of substrate, environment, and mixtures. J Forensic Sci 1996; 41(1):142-145.

Wallin JM, Buoncristiani MR, Lazaruk KD, Fildes N, Holt CL, Walsh PS. TWGDAM validation of the AmpFISTR Blue PCR amplification kit for forensic casework analysis. J Forensic Sci 1998; 43(4):854-870.

Wallin JM, Holt CL, Lazaruk KD, Nguyen TH, Walsh PS. Constructing universal multiplex PCR systems for comparative genotyping. J Forensic Sci 2002; 47(1):52-65.

Wiegand P, Budowle B, Rand S, Brinkmann B. Forensic validation of the STR systems SE 33 and TC 11. Int J Legal Med 1993; 105(6):315-320.

Wilson MR, DiZinno JA, Polanskey D, Replogle J, Budowle B. Validation of mitochondrial DNA sequencing for forensic casework analysis. Int J Legal Med 1995; 108(2):68-74.

Some additional helpful references: