Uses the true Quebec darkfield principle. Contrasted against the darkfield background, the bacteria colonies are bright and readily distinguished from other structures in the agar. Dish holder is adjustable for centering round dishes up to 100 mm in diameter. The case is 10” X 11” X 10 1/2”. With 40 watt lamp, white ruled Wolffhuegel guide plate and tilt leg which may be mounted to give most convenient viewing angle. 110 V. One year warranty.

Electronic Register Model (Reichert 133327000) is operated by a needle-point probe with magnetic ground. When ground and counting probes are both touching conductive agar in dish or plate, an electrical circuit is completed through the integral amplifier, thus activating the digital counter. Each probing action into the colony completes a circuit and is automatically recorded. Reset bar provides immediate zeroing of five-digit counter. One year warranty.