Microscopical examination of bacteria—especially for motility—by observing the organisms in a drop of culture fluid hanging from the underside of a coverslip. The drop is kept from contact with the carrying slide by a cavity in the thickness of the latter, or by separating a plain slide from the coverslip by small portions of plasticene.
Application of a drop of solution to a small glass coverslip. This is then inverted over a glass slide with a depression in it. The contents of the suspended solution can be examined microscopically.