Toxicity testing of medical device materials tested in human tissue cultures.

Rubber and plastic parts of medical devices were applied to human cell monolayers either directly or as aqueous extracts made at different time/temperature conditions. Thirteen rubber and twelve plastic samples were tested. The cultures were observed and photographed by use of a microscope with a camera before and after treatment with the test materials.

Multiplication in Serratia of a bacteriophage originating from Escherichia coli: lysogenization and host-controlled variation.

Temperate bacteriophage P2, originally obtained from Escherichia coli strain Lisbonne, and usually grown on E. coli or Shigella strains, is also able to multiply in some Serratia strains. One of these has been shown to give stable lysogenic derivatives upon P2 infection.