Is possible that unknown culture came out negative for all the three staining te - (Jul/07/2014 )

Today I had first unknown bacteria test, we got 2 different cultures and we had to do Gram test, acid stain and endospore test. Is it possible that one of the cultures came as negative in all three techniques?

Run controls and you;d have confidence in your execution.

florida2001 on Mon Jul 7 20:15:41 2014 said:

Today I had first unknown bacteria test, we got 2 different cultures and we had to do Gram test, acid stain and endospore test. Is it possible that one of the cultures came as negative in all three techniques?

Yes it can.

Endospores are for example most common in gram positives.
So if your gram stain is negative (showing gram negatives) you have already a big change that the endospore test will be negative too.

and the same goes for the acid stain: most of them that are positive are gram positives.