Counting of monocytes.

erythropoietin preparations. as measured with the Limulus lvsate test. ’ As noted by Dr. Fumarola. Limulus amebocyte Ivsate can be used to remove endotoxin from erythropoietin without loss of hormone activity.7 However. such preparations may not be suitable for tissue culture work due to the presence of residual amebocyte protein. Finally. even with removal of the endotoxin, the ratio ofactive hormone to contaminating protein in these crude preparations remains approximately