Thomson’s Ultra Yield Flasks™ (patented) have proven over the last decade to enhance the growth of E.coli & other microbial cells. The patented ask design makes them the work horse of protein and DNA labs worldwide. The Ultra Yield Flasks come in standardized sizes of 125mL, 250mL, 500mL and 2.5L. The asks are designed to be closed on top by using our Enhanced AirOTop™ Seals (patented). These seals are designed to t on the tops of the asks. Enhanced AirOtop™ Seals are sterile, easy to use, and single use. The Enhanced AirOtop™ Seals properties include a 0.2µm resealable sterile membrane barrier providing high air exchange for all types of shake asks. Multiple sizes are available to keep all of your asks covered. Testing has been conducted at multiple customer sites with great results on up to 24 hours of growth. The organisms tested included Protista (Algae), E.coli and other microbes which have resulted in improved cell density, a more neutral pH of the cultures with the increased gas exchange.