Reusable silicone well dividers designed to affix to the surface of Culturewell™ coverslip gaskets, isolating desired reagents inserted into the openings. Culturewell™ silicone dividers are designed to affix to the surface of Culturewell™ coverslip gaskets. Reagents may be pipetted into the openings of well dividers as desired. Silicone well dividers may be re-used by rinsing thorough with distilled water after each use and re-sterilization. Dividers may be sterilized by autoclaving, or alcohol rinse. Unused sterile dividers may be stored by placing them in sterile, covered culture dish until ready to use.