Damian Purcell wrote:
>> Has anybody heard of a GFP variant (or other fluorescent protein) that has
> an excitation maxima around 488nm, but emits in the yellow (580nm) or long
> red wavelengths (670nm). The addition of the Blue variant of GFP is useful
> as a second marker to GFP, but most of the common instrumentation is not
> set up to examine the two excitation and emission wavelengths
> simultaneously. A Yellow or Red fluorescent protein that is stably
> expressed like EGFP and efficiently excited at 488nm would be more useful
> as a second marker with our equipment.
>> This is probably like asking for the goose that laid the golden egg!
Check out the Biocolors from Pharmingen. They have a BioYellow variant,
which although in a baculovirus vector I see no reason why you couldn't
use it in other systems, although obviously not optimised for mammalian
expression like EGFP.
Bioyellow absorbs visible blue light (max 495) and emits a green light
at 509nm, which can apparently be detected visually by daylight. Since
part of the emitted green light is reabsorbed by the protein the net
light emitted is yellow.
Hope this is useful.
I have no connection with Pharmingen.
The opinions expressed in this communication are my own,
and do not necessarily reflect those of my employer.