Yes, dsRed is not the best available; it is a tetramer (obligate I believe).
mRFP1 is a monomerized version that is widely available; here is the reference:
Campbell RE, Tour O, Palmer AE, Steinbach PA, Baird GS, Zacharias DA, Tsien RY.
A monomeric red fluorescent protein.
Proc Natl Acad Sci U S A. 2002 Jun 11;99(12):7877-82.
and mCherry is an even newer version, not widely available as far as I know:
Shaner NC, Campbell RE, Steinbach PA, Giepmans BN, Palmer AE, Tsien RY.
Improved monomeric red, orange and yellow fluorescent proteins
derived from Discosoma sp. red fluorescent protein.
Nat Biotechnol. 2004 Dec;22(12):1567-72.
We haven't seen any problem separating GFP and mRFP1.
Tom Hall wrote: