Bacterial conjugation (a) strain A Mixture of Strain B met bio thrt A and b met+ bio+ thr (b) Cotton plug Medium moved through filter leu+ thi+ leu thi usIng pressure or suctio Strain A Strain B For each sample, wash and plate -10 cells onto Filter minimal medium After incubation cells plated onto minimal medium. No growth met++ bio+ thr* No growth leu+ thi+ cells grow into colonies No growth No growth