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16. Which one of the following purification steps always requires a high initial ionic strength in the sample? A. Ion exchange chromatography B. Hydrophobic interaction chromatography C. Chromatofocusing D. Gel […]

15. In a gel filtration chromatography: A. The large protein will be eluted first B. The small protein will be eluted first C. Both large and small will elute at […]

14. β-lactoglobulin which is a monomer at neutral pH is known to tetramerise at acidic pH of 2. Which one of the following techniques could be effectively employed to demonstrate […]

13. Initial high ionic strength is needed among the following purification techniques in sample? A. Ion-exchange chromatography B. Hydrophobic interaction chromatography C. Chromatofocusing D. Preparative chromatography Hydrophobic interaction chromatography (HIC) […]

12. Which is the best technique to separate two proteins which have the same molecular mass as well as the same isoelectric point? A. Reverse-phase chromatography B. Gel-filtration chromatography C. […]

11. A mixture of three peptides A, B and C is loaded in a C18 reverse-phase chromatography column. A mixture of water and acetonitrile is used as the solvent with […]

10. An enzyme examined by means of gel filtration in aqueous buffer at pH 7.0 had an apparent molecular weight of 160,000. When examined by gel electrophoresis in SDS solution, […]

9. Which of the following statements about HPLC is not correct? A. There are two phases to HPLC: mobile and stationary. B. Separation, identification, and purification of proteins are just […]

8. Which of the following peptides elutes first in size-exclusion chromatography? If a mixture of cytochrome-c, proteinase inhibitor, helicase, serum albumin and RNA polymerase with molecular weights 13.7, 23, 68, […]

7. Mark the correct sequence in which myoglobin (16 kDa), catalase (221 kDa), cytochrome c (13 kDa), myosin (524 kDa), and serum albumin (68 kDa) are eluted from a molecular-exclusion […]