Colony Counters tally the colonies growing on an agar plate so a lab can report colony forming units without the eye strain and miscounts of manual tallying. Automatic models photograph the plate, detect colonies by image analysis with adjustable sensitivity, and count up to 999 colonies in 3 seconds, storing images and results with audit logs for ISO, GMP and FDA compliance. Manual models use a backlit, high-contrast viewing area and a touch pen that registers each mark, suiting teaching labs and low-volume testing. Both export counts to software. Typical uses include microbial limit and sterility testing, food pathogen screening, drinking and wastewater testing and clinical cultures.