Technology Overview
DNA identification has become one of the most important application tools in forensic science. The deconvolution of mixed DNA profiles contributed by multiple people has been one of the most challenging tasks facing these scientists. There is a need for an efficient and accurate method to resolve a sample mixture of DNA into the genotype of each individual whose DNA is contained within the mixture. Drs. T. Wang and J. Douglas Birdwell and their team have developed number of methods to retrieve specific DNA for multiple DNA profiles.
The DNA Forensics Analysis portfolio describes various mechanisms and processes that relate to DNA identification. The portfolio is comprised of four related technology areas:
Least Square Deconvolution–resolving mixtures of multiple DNA samples into discrete profiles for specific individual(s) in the mixture
The deconvolution of mixed DNA profiles contributed by multiple people has been one of the most challenging tasks facing these scientists. There is a need for an efficient and accurate method to resolve a sample mixture of DNA into the genotype of each individual whose DNA is contained within the mixture. Drs. T. Wang and J. Douglas Birdwell have developed a method that uses quantitative allele peak data derived from a sample containing the DNA of more than one contributor to resolve the best-fit genotype profile of each contributor. The resolution is based on finding the least square fit of the mass ration coefficients at each locus to come closest to the quantitative allele peak data. The top-ranked DNA profiles can be used to check against the profile of a suspect or be used to search for a matching profile in a DNA database.
Benefits:• Better quality of fit at each locus (other methods to resolve DNA mixture samples perform a simultaneous fit across DNA loci which compromises the quality of fit)• The method uses direct calculation of the best-fit genotype combination without iteration.• The method is more efficient, simple, and comprehensive compared with other approaches.
Expert System Software–processes to assist experts in “calling” an allele as being one of the key alleles used in identification, where the system can then reevaluate a DNA sample based on an expert’s “call”
Missing Persons/Kinship–identifying individuals based on DNA samples and DNA samples of known family members
identifying unknown individuals based on DNA of relatives and DNA database search techniques. The methods compare DNA profiles from unknown biological specimens to DNA profiles of more than one family member. These methods support identification of a biological specimen using only DNA profiles obtained from related individuals. The methods comprise comparing test DNA profiles from unknown biological specimens to a family pedigree comprising target DNA profiles obtained from multiple biological specimens of family members. The method then ranks and identifies the test profile of the unknown biological specimen most likely to be the individual sought by the family corresponding to the family pedigree. Another method encompasses construction of a database or directed graph of discovered or known relationships between biological specimens and comparison to a graph representing a family pedigree to identify portions of the database or directed graph that correspond to portions of the family pedigree, in order to rank or identify one or more unknown biological specimens as most likely related to one or more family pedigrees.
Benefits:• Method suited for applications that involve large numbers of unknown biological specimen• Method can confirm lineage of an individual using the individual’s pedigree and DNA profiles of an arbitrary number of typed relations• Method can compare individual(s) and pedigree(s) having associated DNA profiles of possible relatives to identify family members• Method is capable of identifying or excluding individual(s) as family member(s) of pedigree(s) using only DNA profiles of putative relatives• Method improves the accuracy, efficiency, and speed of identification of unknown biologicalspecimens in disaster victim and missing person scenarios.
Peaking Fitting–assisting in initial step of DNA analysis/identification by more efficiently extracting allele peak parameters from raw data
Market OpportunityThe DNA sequencing market is generates over $860M in annual revenue currently, and is projected to grow to a $1.3B market by 2013 at a CAGR of 14.7%. DNA forensics technology is responsible for 10% of the overall DNA sequencing market, stemming primarily from sequencing instrumentation, DNA profiling kits, gene mapping software, and DNA fragment analysis software. Genetic research institutions, biotechnology firms, and law enforcement agencies are all converging on this technology area, ensuring a healthy growth rate for the market sector for years to come.