OSAC Lexicon
The OSAC Lexicon is a compendium of forensic science terms and definitions. This terminology tool was created to help bring consistency and understanding to the way terms are used by the various forensic science. Use of the OSAC Lexicon does not replace the need to reference the original published source.
The terms and definitions in the OSAC Lexicon come from the published literature, including documentary standards and technical reports. It is continually updated with the latest work from OSAC units, as well as terms from newly published documentary standards and standards elevated to the OSAC Registry.
Gradually terms are evaluated and harmonized by the OSAC to a single term. This process results in an OSAC Preferred Term. An OSAC Preferred Term is a term, along with its definition, that has undergone review and evaluation by the FSSB Terminology Task Group and has been approved by the FSSB. The FSSB recommends that subcommittees use OSAC Preferred Terms when drafting standards.
The OSAC Lexicon should be the primary resource for terminology and used when drafting and editing forensic science standards and other OSAC work products.
An arrangement of two or more nucleotide or protein sequences that is used to illustrate similarity among those sequences.
One member of a series of possible alternative forms of a DNA sequence found at aparticular genetic location.
One of two or more versions of a genetic sequence at a particular location in the genome.
One of two or more versions of a genetic sequence at a particular location (a locus) in a genome.
The value identified for the allele, either via expert system or by an analyst.
symbol representing the lowest of the three prin- cipal refractive indices of a biaxial crystal.
The result of changing something.
A modification made to a document by any combination of physical, chemical, or mechanical means including, but not limited to, obliterations, additions, overwritings, or erasures.
Equipment used to produce light at various wavelengths to enhance or visualize potential items ofevidence.
Equipment used to produce light (or to restrict light) at various wavelengths to enhance orvisualize potential items of evidence
Equipment used to produce light at various wavelengths to enhance or visualize potential items of evidence.
Equipment used to produce light at various wavelengths to enhance or visualize potential items of evidence.
NOTE A monochromatic light source can be used in examination of an animal’s body to enhance visualization, identification, documentation, and collection of bodily fluids and fibers as potential evidence.
Someone's or something's surroundings, especially as they pertain to the local environment; for example, ambient air and ambient temperature.
A report used to document any subsequent modifications, particularly those that affect or correct an original result or interpretation
A report used to document any modifications from a previously issued report, particularly those that affect or correct an original result or interpretation.
A voluntary national, not-for-profit, independent professional certification board that has been established to promote the highest standards of practice for medicolegal death investigators (see www.abmdi.org).
The United States' largest dental association and the leading source of oral health-related information for dentists and their patients
The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
The unit of electric current that is equivalent to a flow of one coulomb per second; one coulomb is defined as 6.24 _ 1018 electrons.
Any PCR amplification product.
An increase in the number of copies of a specific DNA fragment. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of fragments at specific genetic loci from samples of known and unknown origin for the purpose of generating DNA profiles for comparison.
An increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of DNA at specific genetic loci.
The process by which the number of copies of a specific DNA fragment is increased.
An increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of DNA at specific genetic loci.
Consists of the assessment and documentation of the quality and quantity of the observed class characteristics and characteristics of use of an unknown impression and known footwear or tire.
The interpretation of observed data in a friction ridge impression in order to categorize its utility.
The interpretation of observed data in a friction ridge impression in order to categorize its utility.
The interpretation of observed data in a friction ridge impression in order to categorize its suitability/utility.
A qualified individual who conducts and/or directs the analysis of forensic casework samples, interprets data, reaches conclusions, and/or issues reports concerning conclusions.
A qualified individual who conducts and/or directs the analysis of forensic casework samples, interprets data, reaches conclusions, and/or issues reports concerning conclusions.
A chemical substance to be identified and/or measured.
Includes all targeted compounds in a screening assay, as well as compounds being quantitated and/or confirmed
A set of standards, controls, and/or case samples that are contemporaneously prepared and/or analyzed a particular sequence..
Set of standards, controls, and/or case samples that are contemporaneously prepared and/or analyzed in a particular sequence
A selection of drugs, drug metabolites and other chemicals covered in an analytical testing scheme.
A selection of drugs, drug metabolites, and other chemicals covered in an analytical testing scheme.
A selection of drugs, drug metabolites, and other chemicals covered in an analytical testing scheme.
The lowest amount of an analyte that can be reliably measured in a specimen by a laboratory test; may be a decision point, a limit of detection or a limit of quantitation
The lowest amount of an analyte that can be reliably measured in a specimen by a laboratory test;may be a decision point, a limit of detection, or a lower limit of quantitation.
1) The minimum height requirement at and above which detected peaks on a STR DNA profile electropherogram can be reliably distinguished from background noise; peaks above this threshold are generally not considered noise and are either artifacts or true alleles. 2) A 'Relative Fluorescence Units' (RFU) level determined to be appropriate for use in the PCR/STR DNA typing process; a minimum threshold for data comparison is identified by the specific forensic laboratory through independent validation studies.
The minimum peak height (Relative Fluorescence Units, in RFUs) requirement at and above which detected peaks on a DNA electropherogram can be reliably distinguished from instrument background noise.