Private forensic testing laboratory ensures data integrity with advanced calibration systems.
Tune into any mainstream crime or court television show and it’s clear that DNA test results could mean the difference between freedom and indictment. This also holds true in reality, with genetic test results emerging as one of the top forms of evidence presented in a courtroom. Whether for forensic investigations or paternity questions, genetic test outcomes are often used for life-changing decisions—and accuracy cannot be taken for granted. Producing test results that are accurate and reliable requires the work of an experienced and accredited laboratory.
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As part of its quality assurance program, Orchid Cellmark uses the Artel MVS Multichannel Verification System and the Artel PCS Pipette Calibration System to verify the performance of its automated liquid handlers. (Source: Orchid Cellmark) |
Orchid Cellmark Inc., a genetic testing company, has been conducting paternity and forensic analyses for almost 30 years. Through its laboratories in Nashville, Tennessee and Dallas, Texas, the company conducts DNA forensic analyses for federal, state and local crime laboratories, as well as for law enforcement and private agencies. One of its primary services includes generating profiles for the FBI’s Combined DNA Index System (CODIS), used to streamline crime investigations across the USA.
Orchid Cellmark has tested hundreds of thousands of offender samples and provided results for tens of thousands of cases since its inception. Rigorous quality control programs are in place to ensure that test results are accurate, operations are efficient, and stringent regulatory and accreditation standards are met.
As part of its quality assurance program, Orchid Cellmark uses the Artel MVS Multichannel Verification System and the Artel PCS Pipette Calibration System to verify the performance of its automated liquid handlers. The MVS and PCS provide NIST- traceable measurements of the accuracy and precision of transferred volumes and help eliminate liquid handling error.
Automation made easy
Liquid handling is a core component of day-to-day operations at Orchid Cellmark. Across its facilities, the organization uses more than ten automated liquid handlers, ranging from single probe instruments to 96-channel systems. These are used to conduct a variety of processes, most commonly extraction, quantitation and normalization of DNA. At every step along the way, volume accuracy in pipetting is important.
Using automated equipment has helped the company increase throughput and reproducibility, and minimize human error. When it switched to liquid handling robots, it sought robust technology to verify the performance of its instrumentation—ensuring accurate volume transfers.
“It’s no secret that in forensic DNA testing, the consequences are extreme when results are not correct,” says Kristie Trudeau, manager, Facility Quality Assurance, Orchid Cellmark. “It is extremely important with forensic DNA testing that we use the best quality practices out there because there is absolutely no room for error. With our current liquid handling quality assurance system and tools in place, we are able to track back our testing at every step of the way and be completely confident in our results.”
The majority of Orchid Cellmark’s laboratory processes involve low-volume liquid handling, with transfers as small as one microliter. Inaccuracies as slight as a fraction of a microliter have the potential to affect results. The laboratories also use automated liquid handlers to transfer volumes as high as 900 microliters. It was important that they select calibration equipment to verify instrumentation across this volume range. Additionally, they needed technology able to verify liquid handlers with up to 96-channels.
“With the MVS, we can scale right down to 1 microliter; and with the PCS we can scale all the way up to 900 microliters,” says Trudeau.
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Using automated equipment has helped Orchid Cellmark increase throughput and reproducibility, and minimize the possibility of human error. When the organization made the switch to liquid handling robots, it sought robust technology to verify the performance of its instrumentation to ensure accurate volume transfers. (Source: Orchid Cellmark) |
Streamlined calibration
With the MVS, 96-channel liquid handler calibration is completed quickly as compared to a gravimetric approach, reducing equipment downtime and enhancing the laboratories’ ability to meet deadlines. Based on Artel’s ratiometric photometry technology, the MVS and PCS measure the absorbance of light by two specially formulated dyes to verify volume. Both systems provide traceable measurements of the accuracy and precision of transferred volumes, ensuring standardized volumes and regulatory compliance across Orchid Cellmark’s facilities.
Channel-by-channel information is also important for troubleshooting liquid handling processes. The MVS produces information about each dispensing tip of liquid handling robots with up to 384 channels. The MVS Data Manager software creates summary reports containing the calculated dispensed volumes. Accuracy and precision of the dispensed volumes are measured against user-defined tolerance limits and failing values are flagged in the reports.
By using the Artel systems, Orchid Cellmark is able to optimize its automated liquid handlers when introducing a new test, and to troubleshoot its instrumentation when problems arise.
Maintaining high standards
Laboratory accreditation is a necessity for Orchid Cellmark. The organization’s Nashville and Dallas laboratories are accredited by ASCLD/LAB–International (American Society of Crime Lab Directors/Laboratory Accreditation Board) and FQS-I (Forensic Quality Services International). To meet these standards, facilities must demonstrate that all technical operations and management structure meet ISO 17025 requirements. The laboratories are also accredited by the AABB and hold permits of testing from the New York State Department of Health and the Texas Department of Public Safety.
All accreditations involve an assessment that ensures that the laboratory conforms to accreditation standards, including conducting regular calibrations and documentation of results. Orchid Cellmark meets or exceeds all applicable requirements of these accrediting agencies. With the MVS and PCS, it can calibrate each of its liquid handlers and produce traceable and automatically documented verifications.
On track for the future
Orchid Cellmark takes a number of steps to guarantee the accuracy of its laboratory operations and provide results used to make decisions. With its calibration tools in place, the organization can trust that the results it provides can stand up in a court of law.
About the Author
Paula Pou is a life sciences writer based in New York City.
This article was published in Bioscience Technology magazine: Vol. 34, No. 5, May, 2010, pp. 24-25.