PC. Break-resistant flasks provide an alternative to glass flasks and produce equivalent growth curves with E. coli and S. cerevisiae. Baffles increase mixing. PC has excellent mechanical strength. 500 and 1000 ml sizes feature a straight neck design that accepts standard 38 mm stainless steel or plastic closures. Autoclavable, transparent, graduated. PC. Break-resistant flasks provide an alternative to glass flasks and produce equivalent growth curves with E. coli and S. cerevisiae. Baffles increase mixing. PC has excellent mechanical strength. 500 and 1000 ml sizes feature a straight neck design that accepts standard 38 mm stainless steel or plastic closures. Autoclavable, transparent, graduated.