Abstract: | A reliable cell isolation technique was developed to allow the cultivation of cells from the hamster respiratory tract. Repeated thermolysin treatments and gradient centrifugation yielded a cellculture completely free from contamination by fibroblasts. Viable cells could be isolated from as little tissue as a single hamster trachea, but in vitro proliferation occurred only if the hamster was less than 4 months of age. The cultured cells could be repeatedly passaged and subcultured for weeks by employing normal tissue culture techniques. Morphologically, the monolayers appeared to be a homogeneous population of epithelial cells, and successful cloning of freshly isolated single cells resulted in apparently identical cultures. The epiethelial origin of these cells was also suggested by continued growth in minimum essential medium with D-valine substituted for L-valine. The relative ease with which this cell type can be isolated, cultured, and manipulated in vitro should encourage its application as a model of the respiratory epithelium. |