Naghmeh, I have tried that, but I did not find a primer pair that amplifies all the proteobacteria classes ( alpha, beta, etc). All my searches have led me to around 4 different pairs that I need to detect all the classes. That is why I posted the question. Or, it would also be ok if I could find a sequence of DNA that is preserved in all the classes. I could design a primer from it.
Naghmeh, thanks for the advice. I am totally new to this, is there a tutorial or a guide that I can watch to " retrieve the sequences of type strains for all the above mentioned classes from NCBI. Then, align those sequences and find the most conserved region in the given set of DNA sequences "