1. STANDARD PLATE COUNT PCA or NA growth of wide range of microorganisms not exacting in their nutrition requirements fastidious organisms may not grow colonies may not be from 1 organism sample may not be homogenous enumerates low numbers of organisms

2. Standard Plate Count Pour Plate method AS5013.5-2004 (SupercedesAS1776.1.3) Pour plate method: 1 ml sample + molten agar. NB. Heat of molten agar can cause thermal shock

3. Colony count - pour plate method

4. Calculation This is the traditional calculation. The current standard calculation uses two serial dilution counts. A handout in class will explain this further.

5. Methods: Count colonies in this pour plate. Calculate :- number of colony forming units (cfu) per gram or ml of the food. This is a count of pasteurised milk, therefore the result will be reported as “no. colonies forming units per ml”. If the sample is a solid food item the result will be “cfu per gram”. Which plate will you count? Why? What is the formula for the count of a pour plate?

6. Extract from AS1766.1.3 – Food Microbiology Colony Count - Pour Plate Method See the following for explanations regarding further explanation of counting of colonies and calculations: AS5013.5.10– Counting of colonies ISO7218 1996- Calculations