OSIRIS Home Page - Open Source Independent Review and Interpretation System

Background

OSIRIS is a public domain quality assurance software package that facilitates the assessment of multiplex short tandem repeat (STR) DNA profiles based on laboratory-specific protocols. OSIRIS evaluates the raw electrophoresis data contained in .fsa or .hid files using an independently derived mathematically-based sizing algorithm. OSIRIS currently supports ABI capillary analytical platforms and numerous commercially available marker kits including all CODIS-compliant kits as well as those favored by biomedical laboratories.

OSIRIS searches for peaks by iteratively fitting expected parametric data signatures to the observed data, usually achieving matches with correlations in excess of 0.999. Parametric peak locations are determined with sub-second accuracy and transformed to base pair coordinates. Traditional sizing methods for DNA fragments usually rely on either the local or global Southern methods to interpolate the internal lane standard (ILS) into base pair estimates. OSIRIS departs from this approach, using instead the correspondence between a sample's ILS and an associated allelic ladder to map the time scale of the ladder into that of the sample. This integration of the ladder with the sample permits a straightforward and accurate comparison of sample peaks with ladder locus peaks. Typically, OSIRIS-analyzed sample peaks align within 0.1 base pair of the position within a locus. Thus, in addition to providing reliable and accurate peak analysis, OSIRIS offers two new peak quality measures: fit level and sizing residual.

Based on a laboratory's own protocols, these two measures can enhance quality metrics currently available to assess STR DNA profiles. OSIRIS can be customized to accommodate laboratory-specific signatures including settings sensitive to typical background noise and can include any customized naming conventions or additional internal laboratory controls. When used in complement with other analysis methods, OSIRIS can provide an independent assessment of data and may alleviate the need for human review of passing profiles.

OSIRIS was initiated in response to recommendations of a multidisciplinary advisory group (the Kinship and DNA Analysis Panel, KADAP) empanelled by the U.S. Department of Justice. KADAP was assembled to assist the New York City Office of the Medical Examiner (OCME) and New York State Police (NYSPD) DNA laboratories in the difficult and unprecedented legal and humanitarian challenges the World Trade Center victim identifications raised by developing guidelines and recommendations for management of the identification process, focusing on ways to enhance the number and quality of identifications that could be made. Developed in collaboration with state, local and federal forensic laboratories and NIST, the National Center for Biotechnology Information (NCBI) created OSIRIS using C++ and object oriented design to facilitate the development of add-on applications by those using the program.

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