Replica plating

Sterile velvet is used as a stamp that is first pressed upon the colonies on the original, complete-medium plate and then pressed onto a new, minimal-medium plate, transferring cells from all the colonies of the original plate to the new plate. After an interval to allow continued growth, the original and replica plates are compared. The absence of growth of a colony on the replica plate indicates auxotrophySterile velvet is used as a stamp that is first pressed upon the colonies on the original, complete-medium plate and then pressed onto a new, minimal-medium plate, transferring cells from all the colonies of the original plate to the new plate. After an interval to allow continued growth, the original and replica plates are compared. The absence of growth of a colony on the replica plate indicates auxotrophy

velvet Block Original complete medium plate 0 Stamp sterile velvet on the original complete medium plate to transfer cells from bacterial colonies. Replica plate on minimal medium. 9 Stamp velvet onto minimal medium to make a replica plate. Incubate plate. Missing colonies indicate auxotrophy. 6 Compare replica and original plates to identify auxotrophs that do not grow on minimal medium.