Colourimetric Determination of High-Density Lipoprotein (HDL) Cholesterol Using Red-Green-Blue Digital Colour Imaging

摘要

A rapid, low-cost, and sensitive method was developed for the quantification of high-density lipoprotein cholesterol based on enzymatic colorimetric reactions and digital image analysis. The proposed method was adapted to a 96-microwell enzyme-linked immunosorbent assay plate and imaging acquisition was performed using a conventional desktop scanner. The images were recorded using the red-green-blue color system in which the resolved absorbance for each color channel was used for multiple linear regression. The regression model presented a root mean squared error of calibration and a correlation coefficient (R-2) value of 1.53 mg dL(-1) and 0.995, respectively. Prediction was obtained with a root mean square error of prediction of 2.42 mg dL(-1) and R-2 of 0.993, thereby showing accurate prediction response. A limit of detection of 0.43 mg dL(-1) and precision better than 1.72% reinforced these results. This method was compared with a reference methodology using ultraviolet-visible spectroscopic measurements at 500 nm and no statistical differences were observed at the 95% confidence level, showing the potential for future clinical applications.