Influence of tissue homogenization techniques on levels of estrogen and progesterone receptors measured in calf uterus and human breast tumors.

We have investigated the solubilization of estrogen and progesterone receptors during homogenization of human breast tumor and calf uterus tissue. With chopped human breast tumor tissue, the maximum yield of binding proteins occurred after mechanical homogenization at 4 degrees C with a polytron PT-10 instrument running at setting 5 for 10-15 seconds. With frozen or lyophilised tissue powders the maximum yield of binding proteins occurred after intermittent vortex mixing with buffer over 60 min. at 4 degrees C. The solubilized receptor proteins were stable for at least 150 min. at 4 degrees C. Mechanical homogenization of the tissue powder suspensions resulted in rapid denaturation of the receptors. No improvement in stability was obtained by including 10 mM monothioglycerol and 10% glycerol in the homogenization buffer.