OSAC 2022-S-0040 Standard for Internal 

Validation of DNA Extraction Methods

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OSAC 2022-S-0040 

Standard for Internal 

Validation of DNA 

Extraction Methods

Human Forensic Biology Subcommittee

Biology SAC

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2022-S-0040 Standard for Internal 

Validation of DNA Extraction Methods

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Draft OSAC Proposed Standard

OSAC 2022-S-0040 Standard for Internal

Validation of DNA Extraction Methods

Prepared by 

Human Forensic Biology Subcommittee

Version: 1.0

December 2022

Disclaimer:

This OSAC Proposed Standard was written by the Organization of Scientific Area Committees (OSAC) 

for Forensic Science following a process that includes an open comment period. This Proposed Standard 

will be submitted to a standards developing organization and is subject to change.

There may be references in an OSAC Proposed Standard to other publications under development by 

OSAC. The information in the Proposed Standard, and underlying concepts and methodologies, may be 

used by the forensic-science community before the completion of such companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard is not a 

recommendation or endorsement by the U.S. Government and does not imply that the equipment, 

instruments, or materials are necessarily the best available for the purpose.

To be placed on the OSAC Registry, certain types of standards first must be reviewed by a Scientific and 

Technical Review (STR). The STR process is vital to OSAC’s mission of generating and recognizing 

scientifically sound standards for producing and interpreting forensic science results. The STR shall 

provide critical and knowledgeable reviews of draft standards or of proposed revisions of standards 

previously published by standards developing organizations (SDOs) to ensure that the published methods 

that practitioners employ are scientifically valid, and the resulting claims are trustworthy.

The STR will consist of an independent and diverse panel, including subject matter experts, human 

factors scientists, quality assurance personnel, and legal experts, which will be tasked with evaluating the 

proposed standard based on a comprehensive list of science-based criteria.

For more information about this important process, please visit our website 

at: https://www.nist.gov/topics/organization-scientific-area-committees-forensic-science/scientifictechnical-review-panels. 

Keywords: internal validation, DNA extraction
OSAC 2022-S-0040 Standard for Internal 

Validation of DNA Extraction Methods

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Table of Contents

Scope........................................................................................................3

Normative 

References.................................................................................................3

Terms and 

Definitions.................................................................................................3

Requirements.................................................................................................4

Conformance..............................................................................................5

Annex A -

Bibliography...............................................................................................6
OSAC 2022-S-0040 Standard for Internal 

Validation of DNA Extraction Methods

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1 1. Scope

2 This document details requirements when performing an internal validation of DNA extraction methods 

3 prior to implementation within a forensic DNA laboratory and is intended to be used in conjunction with 

4 ASB 038 Standard for Internal Validation of Forensic DNA Analysis. 

5 2. Normative References

6 The following referenced documents are the foundation of these requirements. For dated references, only 

7 the edition cited applies. For undated references, the latest edition of the referenced document applies.

8 ASB 038 Standards for Internal Validation of Forensic DNA Analysis Methods

9 ASB XXX Best Practice Recommendations for Internal Validation of DNA Extraction Methods

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11 3. Terms and Definitions

12 3.1

13 Concordance 

14 Agreement between DNA typing results. 

15 3.2

16 Degradation 

17 Fragmentation of DNA by chemical, physical, or biological means.

18 3.4

19 DNA extraction

20 A technique used to release DNA from cells in a biological sample. 

21 3.5

22 Inhibition 

23 Prevention of DNA synthesis during polymerase chain reaction by any substance that either directly 

24 interacts with DNA or interferes with the DNA polymerase.

25 3.6

26 Internal Validation

27 Accumulation of test data within the laboratory for developing the laboratory standard operating 

28 procedures and demonstrating that the established protocols for the technical steps of the test and for data 

29 interpretation perform as expected in the laboratory.

30 3.7

31 Sensitivity studies

32 Studies performed during validation of DNA or other test methods designed to define the limits of the 

33 method.
OSAC 2022-S-0040 Standard for Internal 

Validation of DNA Extraction Methods

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34 4 Requirements

35 4.1 The laboratory shall demonstrate concordance of the new DNA extraction method to previously 

36 validated methods or published results.

37 4.1.1 DNA typing results obtained from the new DNA extraction chemistry shall be compared 

38 to results obtained from a previously validated DNA extraction method or published results.

39 4.1.2 Discordant data observed when comparing identical genetic markers using sample(s) 

40 from the same individual, and a potential explanation for any discordant results shall be 

41 documented in the final validation document.

42 4.2 The laboratory shall evaluate the DNA extraction method using known references or casework43 like samples and substrates representative of those typically analyzed by the testing laboratory. 

44 4.2.1 The laboratory shall assess the performance of the DNA extraction method using 

45 different substrates, sample types, and sample conditions (e.g. inhibition, degraded samples, etc.)

46 4.2.2 The laboratory shall conduct a study utilizing mixed biological samples.

47 4.2.3 The laboratory shall compare the results of known and casework-like samples from this 

48 method to results from previously validated methods, where applicable.

49 4.3 The laboratory shall determine the susceptibility of the DNA extraction method to the 

50 introduction of inhibition or degradation. 

51 4.4 The laboratory shall conduct a sensitivity study to determine the limits of the of the DNA 

52 extraction method for obtaining DNA sufficient for analysis.

53 4.5 The laboratory shall demonstrate the precision and accuracy of the DNA extraction method.

54 4.6 The laboratory shall determine the susceptibility of the DNA extraction method to the 

55 introduction of exogenous DNA. 

56 5 Conformance

57 To demonstrate conformance with this standard, the laboratory shall complete and document all 

58 applicable validation studies as described above.

59

60 6 Annex A – Bibliography

61 1. Butler, John. Advanced Topics in Forensic DNA Typing: Methodology. Academic Press, 

62 2012.