1,179,131. Reagent for HCG determination, ORGANON LABORATORIES Ltd. 22 March, 1967 [24 March, 1966], No. 13515/67. Heading B1X. A process for the preparation of erythrocytes for the immunochemical determination of human chorionic gonadotrophin (HCG) comprises treating the erythrocytes with one or more tanning agents and then sensitizing the erythrocytes by treatment with HCG, the sensitization being carried out for at least the last 12 hours of the total sensitization time in the presence of formaldehyde in a concentration below 2% w/v and at a pH between 5.5 and 8. The resulting suspension may be freeze- or spray-dried and the dry powder may be tableted with fillers, for example saccharose, manitol, lactose or urea; lubricants, for example boric acid, starch, Carbowax (RTM), magnesium stearate; disintegration agents, for example starch, alginic acid; phosphate buffers; sodium chloride; disodium EDTA; albumin. Examples refer to sheep erythrocytes treated with formalin and tannin.
