Necessity of prerinsing disposable polypropylene pipet tips.

Piston-actuated microliter pipeta are frequently used to sample and dispense known volumes. These pipets maintain high accuracy and precision when used for rapid serial applications and are ideally suited for radiochemical experiments, because test solutions come in contact only with the disposable polypropylene tips. Their accuracy is affected by temperature differences between the pipet and test solution (1). We found that, even when operating