A Method for Immunological and Chemical Investigations of Body Fluids by Means of Purified Gelatin.

A method is presented whereby certain constituents of serum or other liquids may be concentrated by the swelling of undissolved gelatin. Applications to chemistry, to the study of antibodies, and to the serology of syphilis have been indicated. Colloids, such as proteins and cholesterol, were found to be concentrated as expected. Chlorides also complied with expectation, fully entering the swelling gelatin. An anomaly was found with calcium in blood serum; all of it behaved like nondiffusible material, in contrast with known facts pertaining to dialysis and ultrafiltration.