[just_in]

Hi all,

I was doing some biotech research involving calcein usage, and I encountered problem: Calcein, while being an indicator for metal ions, gives off fluorescence by its own, i.e. without any metal ions. Shouldn't it only fluorescence when it binds some ion? I'm using it according to a manual to detect Mg2+ ions. However, all my samples fluorescence, no matter whether I add metal ions or not.

I'm a bit confused, as a result. If anyone has had any experience using this substance as an indicator, please let me know whether it fluorescences by its own (the solution of calcein) or does it need a metal ion to fluorescence.

Thanx,

Justin

[nj_bartel]

I assume it fluoresces at a different wavelength when bound to an ion?  If that's the case, I don't see an issue.

[just_in]

I assume it fluoresces at a different wavelength when bound to an ion?  If that's the case, I don't see an issue.

I did some runs and it doesn't give off different wavelength. The thing is: it should fluorescence when an ion is bound to it, but should not glow under UV (approx 450 nm wavelength) without an ion bound to it.

The question remains: does calcein fluorescence by its own, with no metal ion bound to it?