Are CF™ dyes sensitive to pH?

Are CF™ dyes sensitive to pH?
FAQ from Biotium
CF dyes are chemically stable within the pH range of at least 2 –11. The fluorescence of most CF dyes is relatively insensitive to pH, except for that of CF405M, CF568, CF620R, and CF633. The fluorescence of these four CF dyes becomes weaker when pH drops below 4.5.
FAQ from Biotium
CF dyes are chemically stable within the pH range of at least 2 –11. The fluorescence of most CF dyes is relatively insensitive to pH, except for that of CF405M, CF568, CF620R, and CF633. The fluorescence of these four CF dyes becomes weaker when pH drops below 4.5.