EMD Millipore PD1504700 PetriSlide for Contamination Analysis (Pack of 100) Combination petri dish and slide holds samples for microscopic examination Sterilized and sized for culturing microorganisms on 47mm diameter membranes Rectangular slide base measures 51mm x 76mm and has rounded corners for mounting on a microscope stage Includes a transparent cover for a clear view of samples Dish is made of molded polystyrene