A simple, effective pipet washer for the clinical chemistry laboratory.

P IPET WASHING has always been a major problem in. a clinical chemistry laboratory. When blood and other body fluids are pipetted the inside of the pipets tends to retain a coating of lipids which is often difficult to remove. On the other hand, the specimens are usually small and utmost accuracy is desired. A pipet which does not drain properly and retains drops of the solution on the inside of the walls contributes greatly to the analytic errors of the laboratory procedure. There are several systems of pipet-washing apparatus commercially available. In some, the pipets are placed in a glass or poiyethylene cylinder and air bubbles are introduced into the cylinder to agitate the washing solution. This results in satisfactory washing of the exterior of the pipets only. The effect on the inside is negligible, since the solution is stagnant there. Another system subjects the pipets, which stand on a wire mesh frame, to jets of detergent solution coming from above and below at the same time. The disadvantage here is that pipets of various dimensions when stacked do not stand absolutely upright. Therefore, the goal of having a detergent solution jet enter the pipet from the bottom and go straight up is rarely achieved. Normally, the jet enters the pipet at an angle,