How might the column chromatography procedure be adjusted or modified to increase the purity of the red fluorescent protein sample?

How might the column chromatography procedure be adjusted or modified to increase the purity of the red fluorescent protein sample?

• A. Use fewer wash buffers with a fixed salt concentration and collect eluates together.
• B. Use more wash buffers with increasing salt gradients and collect eluates in small batches to isolate the red protein.
• C. Skip the washing steps to speed up purification.
• D. Switch to a different resin not suited for hydrophobic interactions.

Answer: (B)

In column chromatography, purity is improved by sharpening the separation between the target protein and other bound proteins during the washing and elution steps. Using more wash buffers with increasing salt gradients helps gradually weaken non-specific interactions, so contaminants are removed in the wash while the red fluorescent protein remains bound until a higher salt concentration elutes it. Collecting eluates in small batches creates fractions that can be tested for where the red fluorescent protein appears; you can identify the fractions that contain the desired protein and combine only those, leaving the impurities behind. This approach is better than skipping washes, which would leave contaminants attached, or using fewer washes with a fixed salt concentration, which provides less discrimination between proteins. Switching to a resin that isn’t suited for hydrophobic interactions would change how proteins bind in a way that likely reduces binding selectivity and overall purification efficiency.

In column chromatography, purity is improved by sharpening the separation between the target protein and other bound proteins during the washing and elution steps. Using more wash buffers with increasing salt gradients helps gradually weaken non-specific interactions, so contaminants are removed in the wash while the red fluorescent protein remains bound until a higher salt concentration elutes it. Collecting eluates in small batches creates fractions that can be tested for where the red fluorescent protein appears; you can identify the fractions that contain the desired protein and combine only those, leaving the impurities behind.

This approach is better than skipping washes, which would leave contaminants attached, or using fewer washes with a fixed salt concentration, which provides less discrimination between proteins. Switching to a resin that isn’t suited for hydrophobic interactions would change how proteins bind in a way that likely reduces binding selectivity and overall purification efficiency.