A. Smaller proteins enter the beads more readily

B. Larger proteins elute first

C. Both A and B

D. Large proteins enter the beads more readily

Gel filtration chromatography separates proteins by size, with larger ones eluting first due to exclusion from bead pores. The correct answer is option C: Both A and B.

Question Breakdown

This multiple-choice question tests understanding of size-exclusion principles in gel filtration columns, commonly featured in exams like GATE Life Sciences.

Option Analysis

• A. Smaller proteins enter the beads more readily: Correct. The column uses porous beads; smaller proteins access internal pores, taking a longer path.

• B. Larger proteins elute first: Correct. Larger proteins cannot enter pores, so they flow through the column’s void volume faster.

• C. Both A and B: Correct answer, as both statements accurately describe the mechanism.

• D. Large proteins enter the beads more readily: Incorrect. Large proteins are excluded from pores due to size.

Introduction
Gel filtration column chromatography, also known as size exclusion chromatography, is a key technique in biochemistry where larger proteins elute first. Smaller proteins enter the beads more readily, delaying their exit, making it essential for protein purification in life sciences research and competitive exams like GATE Life Sciences.

How Gel Filtration Works

Porous beads form the stationary phase in a gel filtration column. Buffer flows as the mobile phase.​

Larger proteins exceed the pore size (exclusion limit), bypassing beads via the void volume for quick elution. Smaller proteins diffuse into pores, extending their path and elution time.

This inverse size-elution order enables separation without chemical interactions.​

Applications in Protein Analysis

• Purification: Isolates proteins by molecular weight for downstream studies.​

• Molecular Weight Estimation: Plots elution volume against standards for size determination.​

• Complex Detection: Monitors protein-protein interactions via size shifts.​

Used in biotech labs for enzyme prep and quality control.​