Ion exchange and affinity chromatography quiz

Which of the following factors does NOT affect ion exchange selectivity?

• Nature of the ion exchange resin

• Temperature of the mobile phase
  
  

• Size of the ions

• Polarizability of the ions

Which of the following ions would likely elute first in cation exchange chromatography at a low pH?

• Na+

• Ca2+

• K+

• Mg2+

Which step in the ion exchange process involves the displacement of counter-ions by solute molecules?

• Equilibration

• Adsorption

• Elution
  
  

• Regeneration

Which of the following is NOT an anion exchanger?

• Diethylaminoethyl (DEAE)
  
  

• Quaternary aminoethyl (QAE)
  
  

• Sulphopropyl (SP)

• Quaternary ammonium (Q)

When the pH of an enzyme solution is below its isoelectric point, what charge do the enzymes carry?

• Negative

• Positive
  
  

• Neutral
  
  

• Zwitterion

In cation exchange chromatography, what is the charge of the analyte?

• Negative
  
  

• Neutral
  
  

• Positive
  
  

• Zwitter ion

What is the primary purpose of affinity chromatography?

• To separate molecules based on size

• To separate molecules based on charge

• To separate molecules based on specific biological interactions
  
  

• To separate molecules based on solubility

Which of the following is NOT a specific biological interaction used in affinity chromatography?

• Antigen-antibody

• Enzyme-substrate

• Cations-anions

• Receptor-ligand

In affinity chromatography, ligands are typically:

• Immobilized onto the protein

• Immobilized onto the column

• Not used at all
  
  

• Used as eluents