An Apparatus for the Continuous Culture of Micro‐organisms on Solid Surfaces with Special Reference to Dental Plaque

In the apparatus described a multi‐channel peristaltic pump is employed to supply precisely controlled amounts of two media (saliva substitute and nutrient broth) to bacterial plaques growing on extracted teeth and other surfaces, in 6 independent chambers under identical conditions. The same pump also removes waste products. A timer‐controlled pneumatic switch programmes the delivery of medium as required. The assembly is compact and is sterilizable in a hospital autoclave as a complete unit. Surface cultures have been established following inoculation with both selected single strains and with mixed bacteria derived from saliva; in the latter instance, the bacterial deposits showed morphological resemblance to natural dental plaque.