Thomson's Ultra Yield™ Flasks have proven over the last decade to enhance the growth of microbial cells & E. coli. The patented flask design makes them the workhorse of protein and DNA labs worldwide. The Thomson Ultra Yield™ Family of products is expanding into new sizes. The Ultra Yield™ Flasks are now available in the following sizes: 125mL, 250mL, 500mL, 1.5mL and 2.5L. When increased safety is needed, a new vented screw cap is available for the 1.5mL and 2.5L Ultra Yield™ Flasks. Ultra Yield™ Flasks in conjunction with the new aseptic Transfer Cap allows for the transfer of cells for scale up or seed cultures. The ability to pump into the Ultra Yield™ Flasks makes filling with media from a bulk source a simple aseptic method. The Transfer Cap in conjunction with the Ultra Yield™ Flasks product line can be used for reagent addition, seeding of larger bioreactors or pumping of media into flasks from large drums or bags, and other liquid media transfers into and out of bioreactors