A point-addressable transfer system for automated sampling, feeding, and expansion of hybridoma cultures

A Dynatech Autoprep liquid sampling system has been modified to perform fully automated aseptic sampling, feeding, and expansion of hybridoma cultures in standard 96- and 24-well culture plates. The system is controlled by an Apple IIe computer, and uses a single teflon probe to transfer culture medium from randomly located wells to EIA plates and deliver fresh medium to the sampled wells. An 'expansion mode' allows suspension of cells for transfer to another plate. The sampling probe may be washed with sterile medium, buffer, or water between each transfer. Any combination of up to 6 assay plates, sterile growth plates, and expansion plates may be operated on at one time, and each transaction is recorded on a floppy disk file. Experiments with various hybridoma cultures indicated that transfers were reproducible, sterility was maintained, and the washing procedure reduced cross-contamination of cultures with other cells or antibodies to negligible levels. The APPLE BASIC computer programs which perform the functions and record the transactions are described in the paper and the Appendix, and are available upon request.