1
$\begingroup$

I am a student, so I hope it is okay to put this question here. I've done the virus plaque assay in a practical recently and have a few questions regarding the plaque count for pfu calculation.

In the plates corresponding to times 0 and 10 mins, a few plaques formed (less than 5 plaques in every plate where plaques could be seen) Should I still calculate pfu with those results, or should I leave it as 0 pfu, and use only plaque counts that are at least more than 10?

|improve this question
$\endgroup$
  • $\begingroup$ Wouldn't the actual number of plaque forming units be more precise? Would it make any if your following steps more difficult or why do you want to simplify it? $\endgroup$ – Marzipanherz Nov 23 '18 at 19:23
  • $\begingroup$ microbiol.org/resources/monographswhite-papers/… $\endgroup$ – canadianer Nov 23 '18 at 20:01
  • $\begingroup$ Sorry, I don't understand what you mean by simplyging? We were told to count the plaques we could see in the petri dishes and calculate pfu from there. What I don't understand if I should calculate pfu even when there's only one plaque in the plate. The protocol says we should choose the plate that has 20 to 300 plaques for the calculation, but I cannot do that with the plates for time 0 and time 10, because all plates have less than 10 plaques in them. In plates of time 0 the maximum I have is 2 plaques. So I don't know whether it's okay to calculate pfu of 2 plaques or it is usually left out $\endgroup$ – Laura Nov 24 '18 at 1:26
  • $\begingroup$ What is the virus? If, for example, it is a bacteriophage, then you would not expect any virus particles to be produced at those early time points, right? $\endgroup$ – mdperry Nov 24 '18 at 3:23

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.