Automated turbidimetric bioassay readout instrument using a multiple flow-cell system.

An instrument has been developed which permits the automatic quantitation of the turbidities of microbiological assay samples. Assay tubes were fed to the instrument at the end of the incubation period. The turbidity readings were automatically converted to digital data which were printed on International Business Machines (IBM) cards and from which potencies were calculated by an IBM computer. The instrument operated at a speed of over 240 tube readings per hour and was totally automatic in sample-mixing, readout, and data recording. The instrument is being used routinely at The Upjohn Co. for the turbidimetric bioassay of vitamins, with a coefficient of variation among repeated turbidity readings of 0.12 to 0.23%.