Page 38 - Academic Press Encyclopedia of Physical Science and Technology 3rd Molecular Biology
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 Encyclopedia of Physical Science and Technology  EN004L-956  June 9, 2001  21:7




















                              DNA Testing in Forensic Science






              Moses S. Schanfield
              Monroe County Public Safety Laboratory



                I. What Is DNA?
                II. Extraction of DNA
               III. Quantitation of DNA
               IV. Current Forensic DNA Testing
                V. STRs Used Forensically
               VI. PCR Setup and Detection
              VII. Usefulness in Detecting Mixtures
              VIII. Individualization








              GLOSSARY                                            pairs per repeat are referred to as short tandem repeats
                                                                  (STRs).
              Alleles Alternate forms of an inherited trait. Such as the  Gene A sequence of DNA which codes for the production
                “A,” “B,” or “O” alleles of the ABO blood group. Sim-  of a specific protein or part of a specific protein, such as
                ple polymorphisms will have as few as two alleles,  a glactosyl transferase (the B allele of the ABO blood
                while hypervariable polymorphisms will have five or  group).
                more alleles, such that the majority of the population  Genotype The genetic type of a person determined ei-
                is heterozygous.                                  ther by the fact that they have two different alleles at a
              Amplified fragment length polymorphisms (AFLPs       locus, or that the individuals parents have been tested
                or AmpFLPs) Polymorphism in length of DNA seg-    to determine what alleles the person has genetically
                ments detected using the PCR process to amplify a  inherited.
                specific segment of DNA, followed by separation us-  Heterozygotes An individual with two different alleles at
                ing electrophoresis. These are normally Variable Num-  a given locus.
                ber Tandem Repeat (VNTR) regions that can have  Homozygotes An individual with two alleles that are the
                different size repeats. AFLPs are classified by the  same.
                size of the repeat, repeats consisting of 10 or more  Locus The place (location) where a specific gene resides
                bases are referred to as large tandem repeat (LTR)  in the human genome. The names of genetic regions
                AFLP, while those containing seven or fewer base  have been standardardized by the International System
                                                                  of Gene Nomenclature (Shows et al., 1987). Inherited
                “Mentioning of commercial products is not an endorsement by The  traits that code for genes usually have a name that re-
              Monroe County Public Safety Laboratory.”            flects its biological function, such as THO1 for the



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