Protein Purification and Quantification

What is the technique used to separate molecules on the basis of size or density by high speed spinning?

• Homogenization

• Centrifugation

• Filtration

• Chromatography

What is the principle behind hydrophobic interaction chromatography (HIC)?

• Separating molecules based on affinity

• Separating molecules based on size/shape

• Separating molecules based on charge

• Separating molecules based on hydrophobicity

Which buffer is used to wash away proteins with few hydrophobic regions in HIC?

• Equilibration buffer

• Binding buffer

• Elution buffer

• Wash buffer

What is the purpose of freeze-thaw in the lysis phase of protein purification?

• To remove cellular debris

• To break the cells open

• To separate the protein from other molecules

• To concentrate the cells

Why does human tears and dogs’ saliva contain high concentrations of lysozyme?

• To break the cells open

• To concentrate the cells

• To remove cellular debris

• To protect against bacterial infections

Where would the enzymes, hormones, and vitamins be found after centrifugation of blood?

• In the supernatant

• In the column side

• In the gel beads

• In the pellet

What is the purpose of the equilibration buffer in HIC?

• To prime the beads in the column for hydrophobic interactions (changes its pH)

• To wash off the protein

• To expose hydrophobic regions of the protein

• To wash away proteins with few hydrophobic regions

Which type of chromatography would be used to separate a protein with a lot of negatively charged regions from other proteins?

• Size exclusion chromatography

• Affinity chromatography

• Hydrophobic interaction chromatography

• Ion exchange chromatography

Answer explanation

A type of chromatography that is based on charge

What is the main purpose of filtration in protein purification?

• To remove cellular debris

• To concentrate the cells

• To separate the protein from other molecules

• To break the cells open

What is the main purpose of size exclusion chromatography?

• To separate molecules based on size/shape

• To separate molecules based on charge

• To separate molecules based on hydrophobicity

• To separate molecules based on affinity