DNA polymorphisms are regions of DNA that vary greatly (are polymorphic) between individuals. These polymorphisms are frequently used to obtain a "DNA fingerprint" of individuals. One polymorphic DNA region, known as the D1S80 locus variably contains between 14 and 40 copies of a 16 base pair repeat; this is an example of a VNTR (variable number of tandem repeats) polymorphism. In this experiment, students isolate their DNA from cheek cells and perform PCR to fingerprint their DNA at the D1S80 locus, using technology used by FBI laboratories in a safe classroom experiment. Students can also quantitatively measure the size of PCR products to determine individual fingerprints. Safe experimental design enables students to perform the experiment using hair or sputum. Includes instructions and materials for 25 reactions. Requires electrophoresis equipment, thermal cycler, white light or UV transilluminator, micropipets, & microcentrifuge, all available separately.