New Release Books by H G Moore

Becton Dickinson has been involved in cell-culture testing of medical devices for the past ten years using WI-38 cells as a human origin in vitro target system. Two modes of tissue-culture testing are used at Becton Dickinson: cytotoxicity score and inhibition of cell growth. To determine score, cell monolayers are scored microscopically as to the degree of morphologically discernable cytotoxicity after incubation for 24 and 72 h with culture media used to eluate test materials. Inhibition of cell growth is determined by culturing cells for 24 h in test material eluate then trypsinizing and reseeding using the elution fluids as growth menstruum. The plates are incubated, and when negative controls indicate a 100% monolayer, the cell monolayers are fixed and stained. The cells are scored microscopically as to the percent of growth inhibition in relation to the negative control. This system has provided a sensitive, reproducible, and short duration evaluation mechanism for biomaterials.