Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation, antibody agglutination test, and PCR analysis. Phase variation was observed by bacterial motility assay and identified by antibody agglutination test and PCR analysis. This comprehensive experiment can be performed to help students improve their ability to use the knowledge acquired in Biochemistry and Molecular Biology.