In Purifying Proteins by Column Chromatography, Elution Can Be Performed

question 87

Multiple Choice

In purifying proteins by column chromatography, elution can be performed in different ways, depending on the type of matrix. For example, bound proteins can be eluted by gradually increasing or decreasing salt concentration in the solution applied to the column. For which of the following matrices do you think increasing and decreasing salt concentration, respectively, are used for elution?

• A) Ion-exchange; hydrophobic
• B) Affinity; ion-exchange
• C) Hydrophobic; affinity
• D) Hydrophobic; ion-exchange
• E) Ion-exchange; gel-filtration

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Definitions:

Conditioned Stimulus

A previously neutral stimulus that, after becoming associated with an unconditioned stimulus, is able to elicit a conditioned response.

Unconditioned Stimulus

In behavioral psychology, a stimulus that naturally and automatically triggers a response without any learning process involved.

Conditioned Responses

Learned reactions that occur in response to previously neutral stimuli after conditioning.

Higher-order Conditioning

A complex form of classical conditioning where a stimulus is paired with a previously conditioned stimulus, rather than with an unconditioned stimulus, to elicit a response.