The polymerase chain reaction (PCR) is a common experiment in upper-level undergraduate biochemistry, molecular biology, and forensic laboratory courses as reagents and thermocyclers have become more affordable for institutions. Typically, instructors design PCR primers to amplify the region of interest and the students prepare their samples for PCR and analyze the results. However, primers can also be designed in undergraduate laboratories with students at this level. In a course that focuses on forensic DNA molecular biology for forensic chemistry students, students have used the Applied Biosystems AmpFlSTR SGM Plus kit that amplifies DNA at eleven regions in a single test tube. It is important for forensic chemistry students to be able to design and analyze a single set of primers and, more importantly, create multiplexes of primers. This enables students to more fully understand how the primers and the kits that are routinely employed by the crime laboratories function. Creating a single set of primers does not demonstrate the extent of design and engineering inherent in creating multiplexes or adequately prepare students for research and careers in the field. The in silico method described herein uses free bioinformatics tools and results in student-designed multiplexes for Combined DNA Index System (CODIS) loci. Sample student data are shown. (Contains 4 tables.)