The classic experiment presented in this problem-solving test was designed to identify the template molecules of translation by analyzing the synthesis of phage proteins in "Escherichia coli" cells infected with bacteriophage T4. The work described in this test led to one of the most seminal discoveries of early molecular biology: it dealt a lethal blow to one of the misconceptions surrounding the mechanism of protein synthesis. Terms students should be familiar with before beginning to solve the test include: Bacteriophage, "E. coli," template, translation, density labeling, radioactive labeling, ribosomes, ribosomal fraction, ribosomal subunits, cesium chloride density gradient centrifugation, sucrose density gradient centrifugation, ribosomal RNA (rRNA), and messenger RNA (mRNA). (Contains 4 figures and 1 footnote.)