FYI

Thanks Joseph. I think my question is not clear. What I meant was, the acceptable percentage of 'unacceptable sputum samples'. For example.....100 people submitted sputum for AFB microscopy. We all know that, all 100 sputum samples will not be perfectly purulent samples and few may be salivary (not good for processing). So, I wanted to know, what is the normally acceptable proportion of unacceptable samples. I mean, if 50 samples out of the 100 are salivary and cannot be processed, something is wrong (poor instructions to patients?).

Still looking for an answer to the above questions.....please help.