One of the things you need to consider is whether the fluorescent AB will aggregate like it does without a tag. I have used regular AB and then stained it with a dye (like ThT) after a given amount of time.

Thanks francis for you comment

I am not interested in AB aggregation now, I just want to measure it inside cells to know the effect of efflux protein on it

Ones upon a time I labelled Ab25-35 with TRITC and they formed nice fibrils and showed no aggregation. However their properties changed: while Ab25-35 loves mica, the labelled one did not (so these experiments never went anywhere and never got published.)

Edited on 08/10/15:

The labelled Ab25-35 fibrils became more hydrophobic via TRITC. I am not sure if the uptake of labelled fibrils would really reflect to the uptake of non-labelled fibrils, since hydrophobic residues can enhance the penetration of molecules through the cell membrane. TRITC and other fluorophores can potentially also affect the interaction of fibrils with other proteins. 

I would try to label the fibrils with as few fluorophore as it is possible. I am not sure what ration could work but having good signal with 1 to 20 (so every 20th monomer is labeled) would encourage me to proceed. Reviewers can still bring up that the surface properties of the fibrils were changed. I would bring it up. 

I would use Thioflavin T.  (Or Congo red. Congo red works in fixed tissue samples for sure. )

thanks Aprad

 Dear Edgar A Dawkins

Can you send me the protocol or paper to find more details.

Is this similar to using confocal microscopy but with a live cells 

Edgar A Dawkins

Thank you very much

i think I will do that and I want to measure the fluorescence inside the cells by using multiplate reader for 96 wells plate. Do you have an idea about that?

Edgar A Dawkins thanks for your notes ,I completely agree with you.

I think after removing the peptide, it is suitable to wash the cells with cold PBS to stop cells activity then read by multiplate reader. 

I want to know the accumulation of peptide inside cells in the presence and absence or specific treatment