The autofluorescence may reduce, but still exist in far-red.

Here is an article that may be helpful:

https://biotium.com/support/tech-tips/tech-tip-battling-tissue-autofluorescence/

"Highly autofluorescent tissue components such as red blood cells and lipofuscin have broad emission spectra, and can also overwhelm far-red immunofluorescence signal. "

maybe addition of dye -ICG ,help if permitted to use

Ok thank you for your answers. I have some issues to count my adoptive transfered cells in the liver of mice. Using a far-red emitting lipidic probe to labelled my cells.

If you want a view of my images :

Spectral confocal imagery; excitation 405nm 514nm : blue DAPI; red = red/far red emitting (>670nm)

20X

https://image.noelshack.com/fichiers/2018/31/1/1532937683-adoptive-transfer.png

It looks like infiltration of lymphocytes around liver vessels

60X

https://image.noelshack.com/fichiers/2018/31/1/1532937683-adoptive-transfer-60x.png

https://image.noelshack.com/fichiers/2018/31/1/1532937683-adoptive-transfer-60x-dapi.png

Here is my trouble, there does not seem to be a nucleus under my cells, even if it looks like lymphocytes.

And 2nd trouble, there is no signal in my control mice.

Thanks for your interest.

MD