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Dn The Hereditary Material

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Deoxyribonucleic acid (DNA) is the hereditary material in humans. It is contained in the nucleus of nearly every cell in the human body and is unique to all individuals except in cases of identical twins. Thus, DNA can be used to identify suspects in forensic casework. DNA can be left behind at forensic crime scenes in a variety of ways. Common sources of human DNA at crime scenes include: saliva, blood, semen, skin, and hair follicles. Saliva samples can provide high-quality and high-quantity DNA, but they do have some special issues associated with them (Nemoda, et al., 2011). Saliva samples contain many different substances that could actively degrade the sample. For example, saliva naturally contains microbes that could contaminate the sample, making it seem like there is more suspect DNA present than there actually is (Nemoda, et al., 2011). Also, saliva fluids originate from multiple glands that secrete at different rates in different people, so some samples may contain less DNA than others (Nemoda, et al., 2011). The DNA evidence acquired at crime scenes is analyzed using Forensic DNA Profiling.
Forensic DNA Profiling is an important tool in forensic science for human identification and paternity testing. Profiling utilizes short tandem repeat sequences (STRs) or variable number tandem repeat sequences (VNTRs) for individualization. STRs are short regions of DNA that are repeated numerous times and can vary in number of copies between individuals (figure 1). VNTR and

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