A colorimetric assay for determination of residual detergent levels in reconstituted membrane protein preparations

A Straightforward Assay for Screening and Quantification of Biosurfactants in Microbial Culture Supernatants

“…MTPs containing VPBO coatings were prepared using a 0.1 mg/ml solution of VPBO (Santa Cruz Biotechnology, California, United States) in isopropanol according to a protocol described previously (Roosloot and Schoen, 2011). Each well in a 96-well plate (Microplate, Greiner Bio-One, Kremsmünster, Austria, flat bottom, polystyrene) was filled with 50 µl of VPBOsolution, and the isopropanol was evaporated under vacuum (Speed-Vac concentrator 5301, Eppendorf, Hamburg, Germany, desiccator function, 60 min, 45 • C).…”

“…Usually, extractions are required as a first step for the determination of biosurfactant amounts and titers. Here, we have adapted a method utilizing surfactant-dependent dye solubilization to quantify detergents in vaccine preparations (Roosloot and Schoen, 2011) for the quantification of biosurfactants in culture supernatants using rhamnolipids as model compounds. In contrast to, e.g., orcinol or anthrone reactions for rhamnolipid detection, this method relies on the surface activity of compound, not on a less specific chemical reaction with reducing sugars in general.…”

“…Currently, the field of biosurfactant biology and biotechnology is rife with mal-reported compounds and their alleged production from various microbes, with many reports often lacking the rigor required to identify and quantify the surface-active compound under study (Irorere et al, 2017). In addition, a robust and reliable method to determine residual levels of cationic and non-ionic detergents (CTAB, C12E8, Tween 80) in vaccine preparations under defined conditions was described (Roosloot and Schoen, 2011). The method is based on the detergent-dependent solubilization of a dye used commercially in ball-pen inks (Miller et al, 1958).…”

Detection of domestic detergent residues on porcelain tableware using laser induced breakdown spectroscopy

“…For example, using spectrophotometric method the phosphate in detergent can be monitored; 7 high performance liquid chromatography (HPLC) is a useful method to detect the nonylphenol polyethoxylates in detergent. 8 Colorimetric method can be used to determine the level of detergent 9 and spectroscopic methods are effective in measuring detergent composition. Attenuated total reectance-Fourier transform infrared spectroscopy (ATR-FTIR) is used in measuring Na 4 EDTA in detergent solution.…”

A precise spectrophotometric method for measuring sodium dodecyl sulfate concentration

“…41 Several methods are known, but none has been widely adopted 42 [15][16][17][18][19][20][21][22]. One method, although both accurate and precise, relies on 43 the separation of SDS into an organic phase [15].…”