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The extraction process is responsible for splitting open the nucleus and releasing the DNA molecules into solution, which is contained inside the nucleus of cells in the body. It is also possible to isolate the DNA molecules from any other cellular material or debris that may be present in a biological sample during this process. Since some of these materials can act as “inhibitors” to later steps in the DNA testing process, it's critical to isolate only the DNA molecules. Hemoglobin and indigo dyes from denim are typical inhibitors used in forensic cases. Manual Phenol-Chloroform (also known as Organic Extraction) and the use of a robotic device named the Maxwell® 16 are two popular methods of extraction used at the BCA.
Polymerase Chain Reaction (PCR) is a method for amplification of DNA (PCR). PCR is a method that allows you to make millions of copies of a given DNA series in just a few hours. This is critical for forensic DNA samples since the amount and content of DNA found at crime scenes is also restricted. The exact heating and cooling of the samples in a thermal cycling pattern for approximately 28 cycles completes the molecular "xeroxing" procedure.
One of the requirements that all DNA research laboratories must follow is to guarantee that the DNA recovered from an extraction comes from a human source rather than a bacterial source. This is accomplished by quantitation, which involves determining the quality and quantity of DNA contained in a sample. Furthermore, since most amplification systems need a limited range of input DNA, evaluating the amount of DNA in a sample is critical for performance in the next stage. At the BCA, this process is performed by using a purchased Quantifiler DNA Human Quantification Kit and then running all samples via an ABI PRISM 7500 Sequence Detection System. Set-up requires about 30-60 minutes, and the operation takes about two hours to complete on the guitar.