Abstract
A computer-linked automated system was developed for counting the number of moving microorganisms under a microscope, that discriminates whether they showed reversals or smooth swimming. The features of the system are 1) commercial I/O devices, and a microcomputer can be used to process the moving pictures, 2) fast processing is accomplished by bit opera-tions for computing the correlation matrix, and pseudo moving objects for processing on the later frames, and 3) a number of cells on the frames are processed in a short time, occluded individuals on a frame are neglected.
The system was used to study the phototactic behavior of Halobacterium halobium. High intensity background illumination caused a decrease in the sensitivity of the behavioral response of the cell to the attractant light.
