MilliporeSigma
  • Home
  • Search Results
  • A visual detection of protein content based on titration of moving reaction boundary electrophoresis.

A visual detection of protein content based on titration of moving reaction boundary electrophoresis.

Analytica chimica acta (2013-04-10)
Hou-Yu Wang, Cheng-Ye Guo, Chen-Gang Guo, Liu-Yin Fan, Lei Zhang, Cheng-Xi Cao
ABSTRACT

A visual electrophoretic titration method was firstly developed from the concept of moving reaction boundary (MRB) for protein content analysis. In the developed method, when the voltage was applied, the hydroxide ions in the cathodic vessel moved towards the anode, and neutralized the carboxyl groups of protein immobilized via highly cross-linked polyacrylamide gel (PAG), generating a MRB between the alkali and the immobilized protein. The boundary moving velocity (V(MRB)) was as a function of protein content, and an acid-base indicator was used to denote the boundary displacement. As a proof of concept, standard model proteins and biological samples were chosen for the experiments to study the feasibility of the developed method. The experiments revealed that good linear calibration functions between V(MRB) and protein content (correlation coefficients R>0.98). The experiments further demonstrated the following merits of developed method: (1) weak influence of non-protein nitrogen additives (e.g., melamine) adulterated in protein samples, (2) good agreement with the classic Kjeldahl method (R=0.9945), (3) fast measuring speed in total protein analysis of large samples from the same source, and (4) low limit of detection (0.02-0.15 mg mL(-1) for protein content), good precision (R.S.D. of intra-day less than 1.7% and inter-day less than 2.7%), and high recoveries (105-107%).

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Potassium chloride, puriss. p.a., reag. ISO, reag. Ph. Eur., 99.5-100.5%
Sigma-Aldrich
Potassium chloride, BioXtra, ≥99.0%
Sigma-Aldrich
Potassium chloride solution, 0.075 M, sterile-filtered, BioXtra, suitable for cell culture
Sigma-Aldrich
Potassium chloride, for molecular biology, ≥99.0%
Sigma-Aldrich
Potassium chloride, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, ≥99.0%
Sigma-Aldrich
Potassium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Sigma-Aldrich
Potassium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Sigma-Aldrich
Potassium chloride, 99.999% trace metals basis
Sigma-Aldrich
Potassium chloride, ≥99.99% trace metals basis
Supelco
Potassium chloride solution, conductance standard B acc. to ISO 7888, 0.01 M KCl
Supelco
Potassium chloride solution, conductance standard A acc. to ISO 7888, 0.1 M KCl
Sigma-Aldrich
Potassium chloride solution, BioUltra, for molecular biology, ~1 M in H2O
Sigma-Aldrich
Potassium chloride, tested according to Ph. Eur.
Sigma-Aldrich
Potassium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Supelco
Potassium chloride solution, for Ag/AgCl electrodes, ~3 M KCl, saturated with silver chloride
Supelco
Potassium chloride solution, conductance standard C acc. to ISO 7888, 0.001 M KCl
Supelco
Potassium chloride solution, BioUltra, ~3 M in H2O
Supelco
ISA (ionic strength adjustment solution: 1 M KCl), 1 M KCl
Sigma-Aldrich
Potassium chloride, puriss., meets analytical specification of Ph. Eur., BP, USP, FCC, E508, 99-100.5% (AT), ≤0.0001% Al
Sigma-Aldrich
Potassium chloride, puriss. p.a., ≥99.5% (AT)
Sigma-Aldrich
Potassium chloride, ACS reagent, 99.0-100.5%
Sigma-Aldrich
Potassium chloride, ReagentPlus®, ≥99.0%