In general terms, cell lines derived from blood (e.g. lymphocytes) grow in suspension cultures. Cells may grow as single cells or in clumps (e.g. EBV transformed lymphoblastic cell lines). For these types of cell lines subculture by dilution is relatively easy. However, for cell lines that grow in clumps it may be necessary to bring the cells into a single cell suspension by centrifugation and re-suspension by pipetting in a smaller volume before counting.
Figure 1.Examples of a suspension cell line. Jurkat E6.1 cells 24 hours (A) and 72 hours (B) post freeze/thaw show typical suspension lymphoblastic morphology. Confluence should carefully be monitored and passaged when cells reach ~80% confluency.