Hi Fedor,

please find attached the absorption spectra for some of the fluorophores Lumiprobe makes (I could not find those for TAMRA and JOE on my computer, although should have them elsewhere - will look for them). I do not have absorption spectrum for SYBR Green in a complex with DNA (the one I have for the free dye can be different).

In short, fluorophores absorb some of the emitted light, and this is one of the reasons for concentrational quenching of fluorescence (non-linear dependence between fluorescence output and dye concentration).

Hi Alexey,

thank you very much for the data!

It is very helpful.

Hope you would be able to find  data on TAMRA and JOE 

Do you know with isomer (5 or 6) of FAM are the data you've sent me?

And thanks for the note on the concentrational quenching, it is very clear.

Best,

Fedor

Hi Fedor, 

my pleasure!

I will look for the data for the other dyes. I am not sure for which isomer the data were measured (maybe even for non-functionalized fluorescein without an extra carboxyl group), but the spectra are very similar for the different derivatives. 6-FAM is more often used for historical reasons - because its emission is marginally narrower than that of 5-FAM, it could make some minor difference for sequencing (FAM is not used for sequencing any more). And also because 6-FAM derivatives are prepared easier. But in current applications, there is hardly any difference.

 Hi Alexey,

Any chance you have spectra data on VIC, ABY, JUN and MP (Mustang Purple)?

those a dyes used in Trio Quantifiler kit .

really appreciate your help

Thanks, Fedor

If you haven't already found info: Thermo Fisher recommends FAM, VIC, ABY, JUN and MP (alternative reference) for multiplex assays on AB7500/Quantstudio platforms.

https://assets.fishersci.com/TFS-Assets/LSG/brochures/TaqMan-Multiplex-qPCR-product-bulletin.pdf

Thanks Rasmus for the link to the brochure, but what i'm trying to find is the actual excitation and emission spectra of those dyes. the brochure shows only a cartoon of emission spectra. I need it to estimate emission flux vs spectral power of the excitation. I understand that manufacturer usually don't publish the such data. What i hopped for was that someone measured the spectra, which is straightforward to do, providing one has a spectrophotometer. Best, Fedor