Certain DNA basepair sequences vary from person to person; for example, in one person a particular basepair sequence may be repeated ten times, while in another person the same sequence may be repeated 25 times. Known as polymorphisms, the repetitions are an identifying factor in a person’s DNA, and thereby can be used for DNA fingerprinting in forensics. When performing this lab activity, your students can separate basepair sequences using electrophoresis and the resulting banding pattern can be used to distinguish one person from the next. Using DNA isolated from their own cheek cells, students amplify a variable DNA region known as a D1S80 locus, electrophorese the DNA, and identify whether the student is homozygous or heterozygous for the D1S80 locus. The kit can be completed in two 90 minute sessions and includes enough materials to run 24 PCR reactions, a teacher’s guide, and student copymaster. A thermal cycler or two water baths, electrophoresis chamber, power supply, and 2–30 mL micropipets, required, are available separately. Note: Coupon included for perishable materials. Redeem with the manufacturer by mail, fax, phone, or e-mail.