Key points are not available for this paper at this time.
A five-stage procedure was used to purify the low mol wt (approx 2.0 S) colony stimulating factor (CSF) in mouse lung-conditioned medium. The final stage, polyacrylamide gradient gel electrophoresis, separated a band with an estimated peak specific activity of 1010 units CSF/mg protein.
Sheridan et al. (Wed,) studied this question.