FIG 4.

Example of the in vitro “tampon sac” method for assessing the effect of tampons (or other devices) on S. aureus and TSST-1 production. The tampon is inserted into dialysis tubing containing S. aureus without culture medium. The tubing is then submerged beneath soft agar. Nutrients required for S. aureus growth may be absorbed from the soft agar. Oxygen required for TSST-1 production is available only from within the tampon. Neither S. aureus nor TSST-1 can penetrate through the dialysis tubing. Upon completion of incubation for a designated time period, stationary at 37°C, the contents of the dialysis tubing are assayed for S. aureus counts and TSST-1 quantities.