water soluble polymers are useful in combination with cobalt redox reagents . when incorporated with the polymers , the cobalt reagents exhibit improved sensitivity compared to fresh solutions of the reagents . in preferred embodiments , the cobalt reagents are coated on a support using the water soluble polymer as a binder . small areas of the coated support are then cut out and placed in a buffer solution to provide a working reagent solution . the solution is particularly useful in the testing of urine for significant bacteriuria .