Answer :
When doing a bacteriophage sensitivity plate, the bacterial strain should be streaked first to form a lawn, and then the phage is added; the answer to the student's question is 2) False.
The correct procedure for doing a bacteriophage sensitivity plate involves streaking the bacterial strain first, forming a bacterial lawn, and then adding the phage. Therefore, the answer to the question is 2) False. You do not streak the phage on the plate first and the bacterial strain second. This method allows for the observation of clear zones, known as plaques, where the phage has lysed the bacteria.
Typically, a titering recombinant phage clones process involves creating a bacterial lawn by plating a high concentration of the bacteria, which grow together rather than as isolated colonies. Serial dilutions of phage are then spread over these bacterial lawns, where plaques will indicate the presence of virus particles infecting the bacteria.
