Determination of urine albumin using micro two-dimensional polyacrylamide gel electrophoresis for pathological analysis of chronic renal failure cat

In the present study, we performed micro two-dimensional polyacrylamide gel electrophoresis (M2D-PAGE) analysis of primary cat urine samples (0.25 μL) collected by non-invasive catheterization. Urine albumin levels were measured after identifying albumin spots by Western Blotting and mass spectrometry by using chicken ovalbumin as a protein standard. The levels determined by M2D-PAGE method were confirmed to be higher than those obtained with the turbidimetric immunoassay that has been been used in veterinary clinical tests employing anti-human albumin antibody and human Alb as a standard sample. These findings suggest that this assay is useful for the early diagnosis of chronic renal failure, including cases classified as stage I according to the International Renal Interest Society (IRIS). We also suggest a new cut off value of 20 mg/dL, which is lower than the previously used 30 mg/dL assumed to be the threshold for no admission.