United Scientific Supplies CCOUNTER Microbiology Colony Counter Professional Manual Counter with Lighted Grid and Activity Guide Lab Grade Equipment

Microorganisms are far too small to count with the naked eye, but they form visible colonies when they join together. When a Petri dish is placed on a lighted base, the grid pattern is illuminated. The 12 by 12 grid contains 1 cm x 1 cm squares. 24 of the squares are broken down into smaller increments of 9 squares, each 1/3 cm in size. To calculate an average colony count per square, the visible colonies are added together and divided by the total number of squares.
Since the Petri dish is close to the light source, it is recommended to use an LED bulb to reduce the risk of heat damaging the sample. The apparatus has a standard bulb base. The power cord has an inline on/off switch.
Overall dimensions are 9" x 9" x 7", 3.1 pounds. Required but not included is a light bulb. Includes activity guide.