Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

This reference recently posted to the MPLSM group is absolutely
essential reading for those engaged in the current debate about
MP excitation of GFPs.

Essentially (and as expected since its a non-symmetrical chromophore)
the excitation spectrum for the various GFP versions is a close
match to the single photon spectrum (at twice the wavelength).
Excitation of eGFP at 800nm is only about 20% of the excitation
at the peak, 860nm.  Unfortunately they don't give wtGFP but
since that has a major excitation peak at 395 is could be good
at 790-800 in MP for those who have non-tunable lasers.

Thanks to Ben Youn for posting this.

                                                Guy


>Here's a reference for TPE spectra for a couple of fluorophores,
>including eGFP, eCFP, eYFP and DsRed
>
>Two-photon excitation action cross-sections of the autofluorescent
>proteins
>Blab GA, Lommerse PHM, Cognet L, Harms GS, Schmidt T
>CHEMICAL PHYSICS LETTERS 350 (1-2): 71-77 DEC 14 2001
>
>Regards,
>Ben Youn


Assoc. Prof. Guy Cox,                 ooOOOOOOoo
E.M. Unit, F09            #       oOOOO  |  |  OOOOo       #
University of Sydney     ###    OOO|  |  |  |  |  |OOO    ###
NSW 2006, Australia      ###  OOO  |  |  |  |  |  |  OOO  ###
Ph:  02 9351 3176        ### OO |  |  |  |  |  |  |  | OO ###
Fax: 02 9351 7682       #####   |  |  |  |  |  |  |  |   #####
                      ==#####============================#####==
http://get.to/gcc       #####                            #####
http://guycox.cjb.net ~~#####~~~~~~~~~~~~~~~~~~~~~~~~~~~~#####~~