Improved isolation of rat lung alveolar type II cells. More representative recovery and retention of cell polarity.

We have developed an improved isolation procedure for rat lung alveolar Type II (ATII) cells which yields a more representative sample of ATII cells with respect to their densities. This procedure includes an initial selection on a density gradient of approximately the complete density range of rat lung ATII cells. Subsequently, to exclude contaminating macrophages and lymphocytes from this fraction, the authors have exploited the fact that the contaminating cells have leukocyte common antigen (LC) on their surfaces, whereas the ATII cells do not. Our procedure yields 2 X 10(7) ATII cells per rat in a fraction which is 90% pure; the cells are immediately available for biochemical or pharmacologic analysis and represent a 90-95% recovery of the ATII cells loaded onto the density gradient. The cells retain their in vivo morphologic characteristics, including their polarity.