The Aerobic Plate Count (APC), also known as the Standard Plate Count (SPC) is used to give a total bacterial count in the milk sample. A high bacterial count is indicative of poor storage (milk is not kept sufficiently cool) or poor hygiene practises.
The APC test involves plating the milk sample with agar into a petri dish and incubating for 72 hours.
An alternative to the APC test is the BactoScan. The BactoScan is an automated instrument which does not require incubation like the plating method. Results have a rapid turnaround time of 24 hours. The test involves staining the bacterial DNA which is then detected and reported as a count.
It is recommended that sheep, deer and buffalo milk using the conventional APC/SPC method. There is an alternative petrifilm test that is available for goat milk, which has a 48 hour incubation period.