ASI Cell Culture Dishes are round and flat "Petri-Dish" Style. Numerical quadrant indicators on the bottom of the crystal Grade Polystyrene provides for easy colony identification, harvesting and visual microscopy. Offered Tissue Culture Treated in four sizes for your convenience. The smaller sized dishes 35mm and 60mm have beveled gripping rings along the edge, to prevent slips and spills. All dishes comes with easy lift-off lids designed to allow for gas exchange, and are sealed in packs of ten to preserve sterility. *Working Volume