Lambda phage assay - (Aug/26/2006 )

I am doing a lambda phage assay and in my protocol it states that the strain with the prophage should be grown to OD600 = 1 and that it is important not to miss this point and then to begin the assay. Why do you think this particular OD is important? Because I've tried the assay once and I think I missed the stated OD so it was OD600=1.5 and my plaques were really hard to count.

Howdy,
Well I must say, I don't quite know what you're doing. You have a lysogen (strain with the prophage), and you are growing it up in order to make a lysate I assume? If so, then going past an OD of 1 wouldn't have anything to do with the size of the plaques that the phage from this lysate make on some other host strain. If the intention is to induce the prophage at an OD of 1, then my assumption is that the strain will produce more phage at that OD (while the strain is still in exponential phase maybe), than if you let it go further (when the strain would be getting into stationary phase). If I'm off base here, give me more info, and maybe I can help.
Cheers