A set of copolymers was prepared via radical copolymerization of N,N-dimeth
ylacrylamide and 7-hydroxy-3-methyl-4-vinylindanone. While poly(N,N-dimethy
lacrylamide) is water-soluble at all temperatures, the copolymers showed a
lower critical solution temperature (LCST), which depended on the compositi
on. Independent of this LCST all copolymers can be used in the dissolved st
ate as protein displacers in combination with anion exchange stationary pha
ses. The indanone group of the polymers is known the chelate calcium ions.
It was therefore also possible to use the polymers to displace acidic (i.e.
, C-site interacting) proteins from hydroxyapatite. The major advantage of
the described displacers over existing agents stems from the fact that they
can be almost quantitatively recovered by thermoprecipitation from the car
rier but also from any given protein zone. Lowering of the temperature rend
ers the polymers again fully soluble and ready for use. No unspecific prote
in coprecipitation was observed under these conditions within our analytica
l means.