Alexa Fluor™ 790 NHS Ester (Succinimidyl Ester) - FAQs

查看更多产品信息 Alexa Fluor™ 790 NHS Ester (Succinimidyl Ester) - FAQs (A30051)

3 个常见问题解答

I am labeling a protein with Alexa Fluor 488 SDP ester. The manual recommends using a sodium bicarbonate buffer at pH 8.3. Can I use a different buffer instead?

Yes. The important thing is to use a buffered solution with a pH between 8.0 and 8.5. Do not use Tris buffer, which has amine groups. Most other buffers will work fine in that pH range. This is also true for other amine-reactive dyes, such as succinimidyl (NHS) esters or TFP esters.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I am not going to use all of my Alexa Fluor succinimidyl ester reactive dye. Can I just make it up in DMSO and store aliquots at -20 degrees C?

This is not recommended. Any trace amounts of water in the DMSO can promote spontaneous hydrolysis over time. Even if using anhydrous DMSO, DMSO is hygroscopic; it readily absorbs moisture from the atmosphere over time. A better alternative is to dissolve the reactive dye in a volatile solvent, make smaller aliquots and then evaporate off the solvent using a vacuum pump. The smaller aliquots of solid reactive dye should then be stored frozen, desiccated and protected from light. Contact Technical Support by sending an email to techsupport@thermofisher.com for the recommended volatile solvent.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I am interested in purchasing Alexa Fluor 790 carboxylic acid derivative to be used as a free dye for a microscope standard. I see that you only offer Alexa Fluor 790 NHS Ester (Succinimidyl Ester) (Cat. No. A30051). Do you have any other recommendations?

We do not offer Alexa Fluor 790 carboxylic acid derivative. We only offer Alexa Fluor 790 NHS Ester (Cat. No. A30051). It is a succinimidyl ester (SE) derivative where the SE functional group (which makes the dye amine-reactive) is attached via a carboxylic acid functional group (thus the nomenclature).
Note: If the reactive moiety is an issue for your assay, then you can bring up the dye in an aqueous buffer, and leave it for about an hour, the SE will hydrolyze and become non-reactive.