The failure or difficulty of cultivating artificially the etiologic agents in a number of so-called virus diseases which are contagious and probably infectious, such as smallpox, influenza, poliomyelitis and others, has often been ascribed to improper mediums. Recently Kendall1 expressed the belief that the difficulty in cultivating viruses was due to a departure of the mediums commonly employed from the environment of the organisms in nature. He pointed out that the artificial mediums usually employed contain protein degradation products (peptones and meat extracts) and little or no unaltered protein, whereas the body tissue possesses the unaltered protein without its hydrolytic products. In order to provide an artificial environment more nearly simulating the natural one in this respect, he prepared a medium (K medium) containing the unaltered protein without peptones or other substances resulting from its disintegration.
With this medium Kendall claimed to have isolated from the blood of three
FRIEDBERG CK. A COMPARATIVE STUDY OF BLOOD CULTURES TAKEN WITH KENDALL AND ROUTINE MEDIUMS. Arch Intern Med (Chic). 1933;52(1):120-132. doi:10.1001/archinte.1933.00160010127012