Abstract: An apparatus for counting microorganism colonies on at least on disposable microorganism culturing medium having a substantially planar substrate. The apparatus has an imaging system for detecting colonies on the substantially planar substrate, and a holder positioning device for storing and queuing one or more holders, each adapted to support one of the substrates. The positioning device moves the holders sequentially into a predetermined position relative to the imaging system so that images can be obtained. The imaging system cooperates with a counting device for counting the colonies using information from several images provided by the imaging system taken at different times as the positioning device cycles the holders past the predetermined location to be imaged. Suitable holders, and a method of queuing and counting colonies on substrates, are also disclosed.

Abstract: A method and system for detecting and identifying microbial colonies in an inoculated growth medium first acquires a first image of the inoculated growth medium. After a selected incubation time interval, a second image of the growth medium is acquired. A difference image is produced by taking the difference between corresponding pixels in the first and second images. Potential colonies are identified within the difference image by locating peak pixels having local maximum pixel intensities within the difference image and having decreasing gradients in a predetermined number of directions. The potential colonies are validated as actual colonies by eliminating those potential colonies that are noise spikes or noise around previously validated colonies.

Abstract: Changes in specified indicia of colony growth in the early stages of incubation are monitored to provide the early detection and enumeration of colonies in the growth medium. Data from images collected at different times is processed to enhance the detection of subtle changes in the specified indicia of colony growth and provide an early indication of the number of colonies present in the growth medium.