Development and Implementation of an Efficient Automated Cell Colony and Plaque Counter

The manual counting of cell colonies, or viral plaques is a laborious, inaccurate task. The work here investigates a low-cost alternative to professional colony / plaque counters. We used an off the shelf webcam, and image processing software (MATLAB) in conjunction with well studied image processing techniques, primarily the watershed transform and the regional maxima transform. With these methods we were able to develop a hardware, software combination that was capable of counting to within 93% of manual counting, in under 10 s for a 90 mm agar plate, and with only one parameter that the user needed to modify. We suggest that this is an effective solution for labs with medium throughput colony or plaque counting.