count the plaques on each plate. record the results in the following chart. note that the results of plates showing more than 300 plaques are to be recorded as tntc (too numerous to count). for this experi-ment, count the plaques on plates that have even fewer than 30 plaques. to determine the total number of phage in the stock solution remember to multiply the average number of plaques per plate by the reciprocal of the final dilution of phage for each plate. this will represent the pfu/ml of the phage stock.