Adsorption of Urinary Proteins on the Conventionally Used Urine Collection Tubes: Possible Effects on Urinary Proteome Analysis and Prevention of the Adsorption by Polymer Coating
Figure 1
(a) SDS-PAGE of adsorbed proteins to poly(MPC-co-BMA)-coated and noncoated urine tubes in two different grades of proteinuric samples. A few distinct protein bands are noted in samples obtained from noncoated tubes. Similar results were obtained in 9 different experiments. (b) SDS-PAGE of adsorbed proteins to 6 different types of poly(MPC-co-BMA) noncoated conventionally used urine collection tubes. AS: poly(acrylonitrile-styrene), PET: polyethylene terephthalate, PS: polystyrene, PP: polypropylene, SBC: styrene-butadiene, and SBC/MS: styrene-butadiene copolymers/methyl methacrylate-styrene. (c) 2-DE of urinary proteins obtained from samples kept at poly(MPC-co-BMA)-coated and noncoated urine tubes. Nine protein spots the intensities of which were significantly greater (P < 0.05) in samples kept at poly(MPC-co-BMA)-coated tubes compared with those kept at noncoated tubes were selected based on the results obtained in seven different experiments. The 2-DE gels are shown for pH 3–10.
