Fig. 1

Results of digesting yaks and cattle lung tissues at the same altitude using different enzymes. (a) and (b) show the results of cell digestion and counting by trypsin. (c) and (d) show the results of cell digestion and counting by Type I collagenase. Black arrows (→) refer to the isolated cells. An asterisk (*) denotes significant difference between the two groups, P < 0.05.