Among the listed protein methods, which has the highest analytical sensitivity?

The Folin-Lowry method is known for its high analytical sensitivity in measuring protein concentrations. This method utilizes a two-step process involving the reaction of proteins with the Folin-Ciocalteu reagent, which results in a colorimetric change that can be quantitatively measured. This sensitivity is primarily due to the strong response generated by the biochemical interactions occurring during the reaction, which allows for the detection of proteins at very low concentrations.

In contrast, refractometry measures the refractive index of a solution, which can be influenced by various factors other than protein concentration, leading to lower sensitivity specific to protein measurement. Turbidimetry, which assesses the cloudiness (or turbidity) of a solution, can also be affected by particle size and concentration, resulting in variable sensitivity. Direct ultraviolet absorption relies on the inherent absorbance of proteins at specific wavelengths but is less sensitive for low concentrations compared to the chemical reaction-driven approach of the Folin-Lowry method.