Ion Exchange Chromatography Concepts

The video tutorial covers the basics of ion exchange chromatography, a technique based on the attraction between opposite charges. It explains the roles of stationary phases, known as ion exchangers, which can be cation or anion exchangers. The tutorial discusses the use of different functional groups and buffers in the process. It also explains how proteins are separated based on their net charge, which is influenced by the pH relative to their isoelectric point. The video provides insights into selecting the appropriate ion exchange method based on protein stability at different pH levels.

What is the primary principle behind ion exchange chromatography?

• Partitioning between two phases

• Attraction between opposite charges

• Separation based on molecular size

• Affinity for specific ligands

Which type of ion exchanger attracts positively charged ions?

• Zwitterion exchanger

• Neutral exchanger

• Anion exchanger

• Cation exchanger

Which functional group is commonly used in cation exchangers?

• Phosphate

• Amino

• Carboxyl

• Hydroxyl

What type of buffer is used with an anion exchanger?

• Positively charged buffer

• Negatively charged buffer

• Neutral buffer

• Zwitterionic buffer

What happens to a protein's net charge when the pH is one unit above its isoelectric point?

• It becomes positively charged

• It becomes negatively charged

• It remains neutral

• It becomes zwitterionic

If a protein is stable at a pH one unit below its isoelectric point, which chromatography method is preferred?

• Anion exchange chromatography

• Cation exchange chromatography

• Size exclusion chromatography

• Affinity chromatography

What is the net charge of a protein at its isoelectric pH?

• Positive

• Variable

• Negative

• Zero

How can proteins be eluted from the stationary phase in ion exchange chromatography?

• By reducing the pressure

• By increasing the temperature

• By adding a detergent

• By changing the pH or ionic strength

What is the role of ionic strength in the elution process?

• It stabilizes the protein structure

• It increases the viscosity of the solution

• It enhances protein binding

• It disrupts protein-stationary phase interactions

Which of the following is NOT a method to elute proteins in ion exchange chromatography?

• Decreasing the temperature

• Changing the pH

• Adding a competitive ligand

• Increasing the ionic strength