Ultra Yield® General Information
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Frequently Asked Questions
- Why do Ultra Yield® Flasks work better than glass flasks, and other disposable baffled flasks for E. coli, Pichia and Schizosaccharomyces pombe?
Ultra Yield® Flasks (patented) are a disposable high aeration shake flask or bioreactor. Ultra Yield® Flasks achieve high aeration with a 6 baffle design that has been optimized for fermentation for E. coli, Pichia, Schizosaccharomyces pombe, and other microbes. They provide good airlift with high speed shaking giving an increase of 10-fold oxygenation When combined with nutrient enriched media and proper pH balance Ultra Yield® Flasks can increase yield significantly. No cutting of aluminum foil or exposure to cross contamination with used flask plugs. Ultra Yield® Flasks allow for scalable results from the 125mL, 250mL and 500mL up to the 1.5L and 2.5L flask volumes.
- How does protein or DNA yield increase with Ultra Yield® flasks?
The Ultra Yield® Flasks act as a bioreactor to grow more biomass or cells per unit volume compared with traditional shaker flasks. With an increase in density there comes an increase in protein or DNA yield. Because they are not oxygen limited microbial cells in Ultra Yield®Flasks can be grown for over 24 hours,. With regard to cell growth microbial cells in Ultra Yield® Flasks do not go from log phase to stationary phase rather, as shown by data from GSK, go to a transition phase. This transition phase allows for continued growth without the anaerobic conditions encountered in traditional flasks that use up the cells’ own nutrients. With Ultra Yield® Flasks while pH maintenance is extremely important, buffering with a non-temperature dependent buffer like MOPS can make a large difference in cell growth. Ultra Yield®Flasks allow for superior growth in shake flasks, and scalable results from the 125mL to 2.5L flask.
- What ratio of liquid media can we have in Ultra Yield® Flasks for E. coli and microbes? What are the recommended shake speeds for E. coli and microbes?
Media ratio depends on the cell type being grown. A general rule for E. coli is to use a 40% fill volume. For example, in the 2.5L Ultra Yield® Flaskfor maximum OD, we recommend using between 500mL and 1L of media. Three to four 2.5L Ultra Yield® Flasks will replace a small-scale fermenter.
- Has anyone tested Ultra Yield® Flasks for acetate concentration? Can you use it as a starter culture for vaccines?
GSK has kindly provided data on pH, OD, and acetate parameters during E. coli growth in both traditional shake flasks and Ultra Yield® Flasks. These studies show that while OD rapidly increases pH remains stable and acetate levels actually decrease over time with Ultra Yield® Flasks. However, in traditional flasks OD increases more slowly while pH drops and acetate levels increase over the same time period.
- What clamps and shakers work best for the Ultra Yield® Flasks?
Ultra Yield® Flasks are designed to shake in 1 inch orbit shakers at high speeds. Higher speeds allow for better aeration, however,at higher speeds it is necessary to use flask clamps rather than sticky tape. Our 125mL, 250mL and 500mL flasks will work with standard shake flask clamps. The 2.5L Ultra Yield® flask can fit into a standard 2L shake flask clamp. New Brunswick and Kuhner shakers have also made a special flask clamp. See our clamp cart below for specific clamp recommendations.
- What media do we put in the Ultra Yield® Flasks?
Recommended media is an enriched media with pH balance around 7.4 . TB, EnBase, Magic Media & Plasmid+® are all good examples of highly enriched medias. The pH balance is most useful with buffers that contain phosphate since these are not temperature dependent.
- Are the Ultra Yield® Flasks disposable or re-usable?
This depends on your individual laboratory policies. Ultra Yield® Flasks are priced to be a disposable bioreactor or disposable shake flask even when also adding in the cost of autoclaving. Keep in mind that when reusing flasks a little residual detergent in the flasks and subsequent ruining of an experiment is more expensive than just using a new flask. However, Ultra Yield® Flasks are autoclavable and reusable. If you were to reuse the flasks we suggest not more than three rounds of autoclaving before disposal as polypropylene becomes brittle over time.
- Myths and legends of growing cultures?
LB is a good media to use for my microbial cultures: Ultra Yield® Flasks perform optimally when using an enriched media like Plasmid+®.
Growing cultures for more than 18 hours will damage my culture: What slows down microbial growth and causes anaerobic growth to occur is an insufficient amount of oxygen and subsequent drop in pH when using traditional shake flasks. Ultra Yield® Flasks give sufficient aeration for up to 7 days of culture at 20°C, and up to 50 hours culture at 37°C.
- What is missing with LB and minimal media?
LB or minimal media is like feeding a person bread and water. People need nutrients and vitamins. This is true with other living organisms such as microbes as well. We all need a balanced diet to grow strong.
- What systems are people using with Ultra Yield® Flasks?
Scientists use Ultra Yield® Flasks on New Brunswick, INFORS HT, Kuhner, and every other shaking platform available.
- We intend to autoclave Ultra Yield® Flasks and media between uses. Can Ultra Yield® Flasks and AirOtop™ Seals or Vented Screw Caps withstand autoclaving? Are flasks, seals and caps sterile and ready to use?
Ultra Yield® Flasks and AirOtop™ Enhanced Seals and Vented Screw Caps come ready to use sterile. It is acceptable to add media and sterilize the flask with the media in it, but do not use AirOtopTM Enhanced Seals or Vented Screw Caps during this process. Sterilization is best done with a piece of Aluminum foil to seal the top. After autoclaving allow the Ultra Yield® Flasks to cool down before using as they do retain heat. Microbes can be destroyed by adding them to flasks taken straight from the autoclave without letting them first cool to the proper temperature.
- How do you grow your cells and media?
We usually prepare a large volume of media and sterilize it in bottles. Then pour the ready-made media into the Ultra Yield®Flasks and add the cells. We find this works best and is easier and faster for multiple runs.
- When should I use a Vented Screw Cap vs an AirOtop™ Enhanced Seal?
Both Vented Screw Caps and AirOtop™ Enhanced Seals offer consistent sterile gas exchange for microbial cultures. AirOtop™Enhanced Seals sare resealable for up to 24 hours.
Recommended culture volumes & orbital shaker speeds (a throw of 1" is generally used for orbital shaking)
|Part #||Description||Use AirOtop™ Seal / Vented Screw Cap||Media (mL)/Flask||Shaker Speed|
|931147||125mL Ultra Yield® Flasks 50/case -- Sterile||899421||40-50mL/flask||300-350 RPM|
|931144||250mL Ultra Yield® Flasks 50/case -- Sterile||899423||75-110mL/flask||300-350 RPM|
|931141||500mL Ultra Yield® Flasks 25/case -- Sterile||899424||125-200mL/flask||300-350 RPM|
|931138||1.5L Ultra Yield® Flasks 12/case -- Sterile||899425 / 899566||250-350mL/flask||300-350 RPM|
|931136-B||2.5L Ultra Yield® Flask 6/case -- Sterile||899425 / 899566||500mL (optimal)||300-400 RPM|
Flask Clamp Compatibility
Refer to the chart below to find the appropriate flask clamp compatible with your shaker.
|Flask Size||Eppendorf®||INFORS HT®||Kuhner®||Fisher Scientific®||VWR®|
|125mL||M1190-9001||12202 ATK 100||SM310100||11-676-013||57019-676|
|250mL||M1190-9002||12203 ATK 250||SM310250||11-676-014||57019-678|
|500mL||M1190-9003||12204 ATK 500||SM310500||11-676-015||57019-682|
|1.5L||ACE1000S||12205 ATK 1000||SM311000||11-676-016||57019-684|
|2.5L||M1190-9005||12206 ATK 2000||SM312500U||11-676-017||57019-686|
End User Questions
Thomson Instrument Company is not affiliated with TB, Magic Media, Enbase, New Brunswick, INFORS HT, Kuhner, GSK or their products