Commercial response:

Dear Tom,

We are specialised in luminescent lanthanide probes for drug discovery
applications. We have an europium cryptate NHS or maleimide available with
a lifetime of about 1 ms in biological media. FRET studies can be
performed easily, we use this in our assays. They are very stable wich is
a great advantage over other lanthanide chelates available. Antibody or
protein-labeling in general is not problematic.
Evidently they can be used for other biological purpuses as well,
including microscopy, but this depends strongly on your budget :-)
If you want more info you can have a look at www.htrf.com or contact our
service department. You can also contact me personally at
[log in to unmask] (I use an old email address on this list)
For the best (in my humble opinion) terbium based probe you can have a
look at www.lumiphore.com
For a recent paper on FRET studies with this kind of probes for membrane
receptor studies see:
D. Maurel et al, Nature Methods 5 (2008) p561-567

Hope this gives some leads,
Kind regards,

Jurriaan Zwier, Ph.D, research scientist at cisbio-bioassays.

> Dear Confocalists,
>
> I am trying to locate some commercial and easy-to-use long lifetime
> fluorphores to time-gate autofluorescence. Ideally they would have to
> last at least 1ms (which is a long time).
>
> The research team I work with makes its own lanthanides organometallic
> fluorophores Eu3+ and Tb3+ which last about 3ms. But I am anticipating
> getting specimens from collaborators who may want to label the
> specimens at their end and lanthanides are not easy to use.
>
> I thought I might be able to find some organometallic transition
> metal-ligand complexes such as ruthenium (Ru II), rhenium (Re I), or
> osmium (Os II) (10 ns to 10 ìs) or some organic fluorophores such as
> Pyrene (400ns) or Coronenes (200ns). But I have had no luck finding
> any, they might not be easy to use and 400ns is cutting it a bit
> short.
>
> One suggestion I have had so far is quantum dots which I need to look
> into. There maybe other options I am not aware of.
>
> I would be grateful if you have any suggestions?
>
> Regards,
>
> --
> Tom Lawson
> [log in to unmask]
> PhD Student,
> Macquarie University
> NSW, 2109
> Australia
>