These treated petri dishes have a hydrophilic surface to promote cell attachment and growth. Lids contain molded spacers to allow gas exchange and stacking rings for increased stability. Bases feature a grip ring for improved handling. All dishes are supplied sterile (gamma irradiated) and come packaged 10/re-sealable bag. Optically clear for improved imaging and observation Consistent flatness allows for even media distribution Manufactured from virgin polystyrene All dishes are supplied sterile (gamma irradiated) 7 to 8 mL working volume 21 cm² growth area