Triton™ X-100 Behaves Similarly to Tyrosine-Containing and Tryptophan-Free Proteins in UV-Vis Spectroscopy

As a known non-ionic, -denaturing detergent and emulsifier, Triton™ X-100 is often used in various biochemical studies including in the isolation of membrane-protein complexes for solubilizing membrane proteins, in the process of periplasmic protein extraction as a component of the lysis buffer, in both indirect immunofluorescence staining and flow cytometry as a permeabilization reagent, etc. It has been shown that the diluted solution of Triton™ X-100 with the optimal pH range of 6.0-8.0 has a significant absorption of UV light. In the present project, we show that the absorption spectrum of Triton™ X-100, when dissolved in 1X phosphate-buffered saline, is similar to that of α-synuclein, as a representative of those proteins lack tryptophan but contain tyrosine as their main UV absorber. These results show that whenever the use of Triton™ X-100 for extracting membrane and periplasmic proteins is inevitable, scavenging it before the characterization of the proteins by UV-Vis spectroscopy, especially the determination of their concentration using Beer-Lambert Law, would be necessary.