How are agents to be tested added to the filter disks Exercises 6-7 and 6-8?
A. The disks are held with sterile forceps, dipped into a beaker of the agent to be tested, and then placed on the surface of the plate.
B. The disks are held with sterile forceps while a drop of an agent is added. The disk is then placed on the surface of the plate.
C. The agents were added to the disks prior to lab.
D. The disks are first placed on the surface of the plates and then drops of the agents are carefully added to the disks.