Substrates coated with selective cell separation or cell culture polymers

A ligand-bearing substrate having a surface at least partially coated with a polymer (P3) comprising structural units represented by the following formulae (1a) and (1b):

• wherein R1 and R2 each independently denote a C1-C5 linear alkyl group, X denotes a hydrogen atom or a C1-C5 linear alkyl group, Y denotes a carboanion (—COO− group) or a sulfoanion (—SO3− group), L denotes a ligand, Q1 and Q2 each independently denote an ester bond, an amide bond, a C1-C10 linear or branched alkylene group or an optionally substituted phenylene group, or a divalent group composed of a combination of any of the above bonds and groups, Q3 denotes a divalent organic group containing a 1,2,3-triazole ring skeleton, m1 and m2 each independently denote an integer of 1 to 200, and n independently at each occurrence denotes an integer of 1 to 10.