Question

describe three techniques used to identify microorganisms

Answer 1

microscopy
Culture
Serology

try Wikipedia for definition.

Answer 2

okay so i looked it up and there were several so I'm just going to copy paste it:

Many identification techniques:

Many different criteria may be employed for identification, though it is often desirable to employ the easiest techniques possible.

What techniques and tests may be necessary, however, depend on what organism is being identified and how much detail into the organism's classification you are interested.

Techniques include:

morphological identification
differential staining
use of differential media
serological methods
flow cytometry
phage typing
protein analysis
comparisons of nucleotide sequences