Methods for the analysis of microcolonies of bacteria and yeast

1. A method comprising:

a) filtering a sample containing bacteria and yeast through at least one filter;

b) treating the filter or filters with a medium which facilitates the growth of the bacteria and yeast;

c) growing the bacteria and yeast on the filter or filters to thereby produce colonies or microcolonies of the bacteria and yeast;

d) fixing the colonies or microcolonies to the filter or filters;

e) treating each filter under suitable hybridization conditions with one or more enzyme labeled PNA probes wherein, each PNA probe comprises a probing nucleobase sequence complementary to a target sequence in the nucleic acid of the bacteria and/or yeast;

f) removing excess enzyme labeled PNA probe from each of the filters;

g) determineing enzyme activity remaining on each filter to thereby identify or enumerate colonies or microcolonies on the filter or filters.

2. The method of claim 1 , wherein identification or enumeration of the colonies or microcolonies depends upon relative growth rate.

3. The method of claim 1 , wherein identification or enumeration of the colonies or microcolonies depends upon colony morphology.

4. The method of claim 1 , wherein one filter is used to identify or enumerate at least one bacteria and at least one yeast.

5. The method of claim 1 , wherein two or more filters are used; at least one filter for each organism to be identified or enumerated.

6. The method of claim 1 , wherein two or more enzyme labeled PNA probes are used; at least one PNA probe for each organism to be determined.

7. The method of claim 1 , wherein the enzyme labeled PNA probe is a soy bean peroxidase labeled PNA probe.

8. The method of claim 1 , wherein the enzyme labeled PNA probe is an orthogonally labeled PNA probe comprising both a fluorophore and enzyme.