The frequency of gene transfer (Roberts et al., 2001) was expressed as the number of transconjugants per donor or recipient cell, whereby number of colonies x dilution factor = number of CFUs per filter.
If mating between selected donor and recipient did not produce any transconjugant, do we still calculate transfer frequency using the same formula? I notice certain studies describe the frequency to be less (
Dear Ainaa,
There are times when we need an answer that is not zero - even when we fail to detect anything in our assays. With respect to transconjugation frequencies (or transformation frequencies), all you need to do is calculate the frequency as if you had one colony on your plate - this would give you the 'less than' value that makes sense of the experiment by assuming that if you had plated out just a bit more sample, you would have actually got that colony!
Andrew
Thank you Andrew J Spiers . I am actually doing conjugation inhibition study therefore wondering if I should just state the compound that I'm using is working with no transconjugant obtained or I should still calculate the conjugal transfer frequency.
Dear Ainaa,
Always report quantitative data, especially '< 0' type results, as this shows that you were in a position to calculate real numbers and were more observant than (say) saying 'there were around 50 colonies' or something inaccurate like that. Furthermore, if you have replicates, report the mean ± standard error (our some other error measurement) and try to do the appropriate statistical tests to 'prove' what your general impressions are.
Andrew
- Badges
- Science topic
- Similar topics
- Control Systems Engineering
- Filtering