In 1923, one of us (J. A. T.) noted that human placental serum blanched the rash of scarlet fever. Since then, we have carried out a comparative study of the intradermal reactions to placental serum and the corresponding reactions to scarlet fever antitoxin, maternal serum and convalescent scarlet fever serum. The effects of ether extraction, of filtration and of catalyzation on the blanching powers of the various serums were studied.
METHOD OF PROCEDURE
Placental serum was collected at birth by milking the cord into sterile containers. Mother's serum was obtained twice, one week before and one week after the birth of the infant. All serum, placental or otherwise, was centrifugated; the clear supernatant fluid was inactivated at 56 C. for two hours and then bottled.Convalescent scarlet fever serum was obtained at least twenty-one days after the acute illness had begun, and was likewise inactivated. When serum was extracted by
TOOMEY JA, AUGUST MH. STUDIES IN SCARLET FEVERVII. BLANCHING WITH PLACENTAL SERUM. Am J Dis Child. 1929;38(5):953-959. doi:10.1001/archpedi.1929.01930110052008