Why did my 200 mM L-Glutamine precipitate out of solution when I thawed it?
When L-glutamine is in a concentrated stock solution it easily precipitates when cooled. Warming the solution briefly in a 37C water bath with gentle swirling will dissolve the precipitate. Do not use the product unless the precipitate is fully dissolved.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
Why does L-Glutamine (200 mM) (Cat. No. 25050149, 25030081, 25030164) solution have “Product of Brazil” on the label?
L-Glutamine (200 mM) (Cat. No. 25050149, 25030081, 25030164) solution is made in the USA from a raw material glutamine powder manufactured in Brazil. The country of manufacture of a component that has been subjected to manufacturing or processing operations in more than one country is the last country in which the component has been “substantially transformed”. A “substantial transformation” occurs in a country when a product emerges from a manufacturing process with a name, character, or use different from that of the original material(s) subjected to that process.
Diluting, purifying, sorting, testing, packing, repacking, or affixing labels to a product in a country does not constitute a “substantial transformation” in that country, hence the label must bear the country of the original raw material origin.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
My order of L-Glutamine (Cat. No. 25030081) arrived frozen. Is it stable?
If L-Glutamine is completely or partially frozen, it is still stable. It becomes unstable when stored for extended periods of time completely thawed, especially above 2-8 degrees C.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
What is your recommended method for thawing L-Glutamine before adding to cell culture media?
We recommend thawing at 2-8 degrees C and then warming at 37 degrees C until the material goes into solution. Mix it as it warms up to spend minimal time at elevated temperatures before you aliquot it.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.
Why did my 200 mM L-glutamine precipitate when I thawed it?
When L-glutamine is in a concentrated stock solution it easily precipitates when cooled. Warming the solution briefly in a 37 degrees C water bath with gentle swirling will dissolve the precipitate. Do not use the product unless the precipitate is fully dissolved.
Find additional tips, troubleshooting help, and resources within our Cell Culture Support Center.