In this hands-on MiniLab students explore the basics of Polymerase Chain Reaction (PCR) using the genome of Bacteriophage Lambda, a classical model system for molecular genetics. Students will use PCR to amplify three segments of the Lambda Phage genome using three different sets of primers and use the supplied genome sequences and primer sequences to predict the size of the fragments. Students will test their predictions by running the products of the PCR reactions on an agarose gel. This guide provides sample data answers to questions and explain steps in the protocol.