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Expi293™ Met (–) Expression Medium - FAQs

查看更多产品信息 Expi293™ Met (–) Expression Medium - FAQs (A4096701)

4 个常见问题解答

I am performing L-selenomethionine labeling and getting very low protein yields. What could be going wrong?

L-selenomethionine is a known cell toxin. Therefore, it is important to grow cells in the present of this amino acid for the shortest amount of time required to achieve maximal labeling. We recommend adding L-selenomethionine to the culture just prior to transfection (in Expi293 Met (-) Expression Medium). You may also starve cells for 6 hr by culturing cells in Expi293 Met (-) Expression Medium (without supplementation) and then proceed with L-selenomethionine add-back and transfection.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

I'm culturing my Expi293F cells in Expi293 Met (-) Expression Medium but they are not growing. What could be going wrong?

Expi293 Met (-) Expression Medium does not contain methionine, which is an essential nutrient for cell culture. Therefore, methionine supplementation is required. For methionine labeling, cells should be grown in Expi293 Met (-) Expression Medium and starved (i.e., grown in the absence of methionine supplementation) for 6 hr prior to addition of 13C-methyl-L-methionine, or similar methionine isotope.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

How do I use Expi293 Met (-) Expression Medium for methionine protein labeling?

Expi293 Met (-) Expression Medium is not intended to support long-term cell culture as the media is deficient of methionine, an essential amino acid for cell survival. When you are ready to start your labeling experiment, transfer Expi293F Cells growing in Expi293 Expression Medium to Expi293 Met (-) Expression Medium by centrifuging the cell suspension (200 x g for 5 min) and resuspending the cell pellet in Expi293 Met (-) Expression Medium. Cells may be starved for 6 hr prior to supplementation with L-selenomethionine, isotopic-labeled methionine, or other derivatives.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.

What is the difference between Expi293 Expression Medium and Expi293 Met (-) Expression Medium?

The formulation of Expi293 Met (-) Expression Medium is identical to that of Expi293 Expression Medium except for the absence of methionine. Expi293 Met (-) Expression Medium allows for the addition of isotopic-labeled methionine or derivatives to promote labeling of proteins for structural analysis.

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.