This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Structure & Function of Proteins), Subject name: Biochemistry
[{'content': 'In SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis) proteins are separated on basis of: (PGI June 2009) \nSelect and explain. \nA. Mass, B. Charge, C. Density, D. Molecular weight', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: A (Mass) & D (Molecular weight) "The most widely used method for determining purity of of a protein is SDS-PAGEfi-sodium dodecyl sulphate(SDS).ln this polypeptide separates based on their relative molecular mass (Mr)"- Harper 27th/24Methods Used for Protein Separation & AnalysisTechniqueProtein Property ExploitedElectrophoresisQDenaturing gel (SDS-PAGE) QMassQ (Motecular weight)Native gelMass/Charge2 D gelsMolecular weight & plIEF(Isoelctric focussing)plflsoelctric point)Chromatography Methods(r)Ion- ExchangeChargeQGel FiltrationSizeQ or Molecular weightQAffinityBiological activityReversed phaseHydrophobicityHydrophobic InteractionHvdrophobicityChromatofocussingPlBulk MethodsQCentrifugationMassQ/DensityFiltrationSizeQAmmonium sulphateSolubility', 'role': 'assistant'}]