Non-radioactive mini or maxi cells?

[M_COYNE at DELPHI.COM]

Does anyone know of a protocol for detecting the number and size of proteins
encoded by DNA cloned into a vetor, a la Mini or Maxi cells, that does not
rely on the use of radioactivity?  In this time of non-radioactive
alternatives to everything, this one seems (to my knowledge) to be missing.
Is there a way to label proteins in vivo without 35S or some other
radioisotope?

Comments or suggestions greatly appreciated...

Mike
M_Coyne at Delphi.com