Hope this is in the right place, apologies if not. We have studied green flourescent protein GFP and others (RFP, CFP etc) as a means of analysing an organism / sample, you need two that have unique fluorophores. We have also studied the use of FRET pairs such as florecein-florescien or florecein-rhodamine for studying interatomic distance / molecular structure. My question is are flourescent proteins and FRET pairs related or are they for completely different analyses? Think I'm getting the two mixed up, or are they related? i.e. do FP's contain the chemical in Fret pairs? Hope this question makes some kind of sense im really not a biologist!