Immunochromatographic assay to detect α-tubulin in urine for the diagnosis of kidney injury

Backgrounds: Shortening of primary cilia in kidney epithelial cells is associated with kidney injury and involved with the induced level of α-tubulin in urine. Therefore, rapid detection and quantification of α-tubulin in the urine samples could be used to the preliminary diagnosis of kidney injury. Methods: Cellulose-based nanobeads modified with α-tubulin were used for the detection probe of competitive immunochromatographic (IC) assay. The concentration of α-tubulin in the urine samples was determined by IC assay and compared with the amount determined by Western blotting analysis. Results: The relationship between α-tubulin concentration and the colorimetric intensity resulted from IC assay was determined by logistic regression, and the correlation coefficient (R²) was 0.9948. When compared to the amount determined by Western blotting analysis, there was a linear relationship between the α-tubulin concentrations measured by the two methods and the R² value was 0.823. Conclusions: This method is simple, rapid, and adequately sensitive to detect α-tubulin in patient urine samples, which could be used for the clinical diagnosis of kidney injury.