Over the past twenty-five years, the emergence of DNA testing has changed the landscape of forensic science. While DNA testing is often used in criminal cases, it is estimated that 25% - 35% of all evidence samples submitted to crime laboratories fail to produce an informative DNA result with standard methods, frequently due to DNA degradation or low DNA quantity.1 Besides hampering investigations, these challenging samples frequently require labor-intensive re-processing before being abandoned, further increasing inefficiencies that contribute to increased costs, lengthy turnaround times, and casework backlogs.
In addition, a number of sample types commonly found at crime scenes, such as shed hairs, are often not even submitted for DNA testing due to the low likelihood of obtaining a usable result. A small percentage of these samples are outsourced to specialized laboratories for mitochondrial DNA (mtDNA) sequencing; however, mtDNA sequencing is limited by reduced discrimination power (~ 1 in 4-5000), inability to differentiate offspring of the same maternal lineage, excessive cost, long turnaround times and the need for a specialized workflow that is challenging for most forensic DNA testing laboratories to implement.
New Alternatives for Forensic Genetics
To address the limitations described above and expand the potential of DNA testing, InnoGenomics has developed innovative solutions that are fully compatible with the current qPCR, PCR and capillary electrophoresis (CE) platforms commonly used and validated within most forensic laboratories. These include:
- InnoTyper® 21 – a small amplicon DNA typing system containing 20 Retrotransposon Insertion Polymorphism (RIP) markers and Amelogenin. Using a proprietary mini-primer design, this kit has amplicons ~60-125bp and can provide discriminating results from extremely low-level and/or degraded forensic samples including bone fragments or single hair shafts. The RIP markers in this kit are stable and identical by descent, providing valuable utility for difficult kinship, missing person and mass disaster victim identification cases.
- InnoQuant® – a robust real-time qPCR assay for simultaneous assessment of human DNA quantity, quality and integrity. The use of high copy number retrotransposable element targets provides excellent sensitivity and reproducibility. Comprehensive and reliable sample assessment enables forensic laboratories to confidently screen samples and make informed workflow decisions, significantly reducing downstream re-processing and improving analysis success rates. Forensic analysts can use this kit to easily identify when sample processing should be stopped, modified, or if the sample should be preserved for alternative testing methods such as InnoTyper®.
- InnoQuant® HY – a robust real-time qPCR assay for simultaneous assessment of human and male DNA quantity, quality and integrity. The use of high copy number retrotransposable element targets provides excellent sensitivity and reproducibility. Forensic analysts can use this kit to accurately determine male DNA quantity in challenging male-female mixtures (i.e. sexual assault samples), and easily identify when sample processing should be stopped, modified, or if the sample should be preserved for alternative testing methods such as InnoTyper or Y-STR testing.
1Estimate based on market research including a 2013 survey of U.S. crime laboratories conducted by InnoGenomics. Percentage range varies depending on laboratory sample submission and screening policies.