Effect of Acid Concentration on Chromogen Formation from Hexoses in Sulfuric Acid-Based Reactions

A colorimetric determination for glycosidic and bile salt-based detergents: applications in membrane protein research

“…1. The visible band at 490 nm arises from p-semiquinonoid chromogen formation via the addition of the furfural aldehydic group to the hydroxyl moiety of phenol, and the shoulder in the region at 400-440 nm arises from p-sulfonation of the phenol [22,23]. The yield of this side product in this single-step reaction setup is dependent on the specific reactivity of the furfural derivative with phenol.…”

Reconstitution of Membrane Proteins

“…9. Turbidity measurements can be used to monitor reconstitution and a detergent assay can be performed to confirm complete detergent removal (within the sensitivity limit of the assay) (Mallya & Pattabiraman, 1997). 10.…”

Measurement of detergent concentration using 2,6-dimethylphenol in membrane-protein crystallization

“…Based on the work of Mallya & Pattabiraman (1997) and of Urbani & Warne (2005), a 2,6-dimethylphenol-sulfuric acid reaction was explored. Initially, 5 ml protein sample was diluted with 220 ml deionized water in a SafeSeal 1.5 ml tube (Starstedt, Germany).…”

“…However, the proposed method uses a relatively large sample volume. This work explored the use of 2,6-dimethylphenol as a colorimetric agent with increased absorbance (Mallya & Pattabiraman, 1997). This substitution has allowed the sample consumed to be significantly reduced.…”