The invention relates to a novel polymethine dyes containing at least one acylsulfonamido
group of the formula (I)
##STR1##
in which n, Y, A and R have the meaning given in the claims, and at least one
compound of the formulae (a) to (n) given in the claims. The polymethine dyes according
to the invention are suitable for use as dyes and/or labels, in particular for
staining or labeling biomolecules.