Plaque Assay Protocol for Pseudoalteromonas
First , autoclave the top agar to melt it .
While the autoclave is running , let your bottom agar plates warm to room temperature and label them and make whatever dilutions of your phages you plan to plate .
Note : it is wise to plate one dilution higher and one dilution lower than what you calculated as optimal .
Aliquot the agar into tubes and place in 40°C water bath .
Pipet 100 μl of your phage sample onto the plate .
Remove the agar tube from the water bath and add the host to it using a 1 ml or 5 ml pipettor .
Add 3.5 ml of the agar / host mixture to each plate .
Swirl the plate to spread the agar making sure it covers the whole plate .
Leave the plates on the bench overnight .
Count or pick plaques the next day
