Nalgene 4110 Polycarbonate Baffled Culture Flasks can be used for E. coli and S. cerevisiae at room temperature. These polycarbonate flasks produce growth curves equivalent to those of glass flasks. Baffle design supplies the mixing, aeration, and gas exchange needed for effective cell culture, fermentation, and genetic engineering procedures. Molded neck ridge acts as a finger stop for consistent sterile technique. The 500 and 1000mL sizes have a straight neck design that accepts standard 38-mm stainless steel or plastic closures. Autoclavable.