Cultures of pig macrophages.

Freshly collected blood from pigs was defibrinated with glass beads. The white cells were collected on a Ficoll-Hypaque mixture and grown in RPMI 1640 medium containing 20 per cent fetal calf serum. Monocytes adhered to the plastic or glass flasks and the erythrocytes and lymphocytes remained in suspension. The adherent cells assumed the appearance of macrophages and the mean cell size at eight days was 40 mum. Phagocytosis was demonstrated and, in the first few days, incorporation of tritiated thymidine occurred. Cells remained viable in culture for more than eight weeks. Histo-chemical studies and the appearance of the cells under the electron microscope are described.