Plate should have fewer than 200 colonies if accurate colony counts are desired.(8) Similar appearing colonies growing
in close proximity, but not touching, should be counted as individual colonies. Colonies with different morphology or
color should be counted as individual colonies. When spreading colonies are present, a representative portion of
colonies in a spread-free area should be counted. This is only done if the area covered by the spreaders does not exceed
one-half of the plate area.
Refer to specific technical information sheet for interpretation of typical colonial morphology for the type of medium
used.
Consult listed references for more detailed information concerning plate count methods.(8)