Q.17 Vertical gel electrophoresis is routinely used for the seperation of-
I. Protein
2. DNA
3. RNA
4. Carbohydrate and lipid
Vertical gel electrophoresis is routinely used for protein separation via SDS-PAGE. The correct answer is option 1: Protein.
Technique Basics
Vertical systems employ polyacrylamide gels with small pores (~10-200 nm) and discontinuous buffers for high-resolution separation. Unlike horizontal agarose gels, vertical setups prevent acrylamide polymerization inhibition by oxygen, enabling precise protein sizing.
Option Breakdown
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1. Protein: Correct. SDS-PAGE in vertical format denatures and separates proteins by molecular weight; standard lab routine for purity checks and Western blotting.
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2. DNA: Incorrect as routine method. Horizontal agarose gels suffice for most DNA (larger pores); vertical polyacrylamide used rarely for high-res sequencing ladders.
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3. RNA: Incorrect. Horizontal agarose/formaldehyde gels standard for RNA integrity (RIN); vertical not routine due to RNase sensitivity and gel fragility.
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4. Carbohydrate and lipid: Incorrect. These use TLC/paper chromatography, not gel electrophoresis; vertical gels unsuited for non-charged amphipathic molecules.
Vertical Gel Electrophoresis Separation: Protein DNA RNA Carbs Lipids Guide
Vertical gel electrophoresis is routinely used for the separation of proteins through SDS-PAGE, not DNA, RNA, or carbohydrates/lipids. This vertical gel electrophoresis guide targets GATE Life Sciences students, explaining polyacrylamide advantages, routine applications, and why option 1 dominates.
Vertical vs Horizontal
Vertical: Cathode (top)/anode (bottom) chambers; buffer flows only through thin (<2 mm) polyacrylamide gel for voltage control. Ideal for proteins (linear SDS-coated rods sieve by size). Horizontal: Agarose slab for nucleic acids (gentle, larger pores).
| Molecule | Routine Vertical? | Gel Type | Reason |
|---|---|---|---|
| Protein | Yes | Polyacrylamide (SDS-PAGE) | Size resolution; standard |
| DNA | No | Agarose (horizontal) | Routine; vertical only sequencing |
| RNA | No | Agarose/formaldehyde | RNase issues; integrity checks |
| Carb/Lipid | No | TLC/chromatography | Non-electrophoretic |
Why Proteins Rule Vertical
Acrylamide’s polymerization suits vertical pouring between plates; SDS ensures uniform charge/mass. Resolution: Proteins <1 kDa separable vs horizontal’s blunt nucleic acid ladders. Apps: 2D-PAGE (IEF + vertical SDS).
Exam Tips
Mnemonic: Vertical = Proteins (Vertical Polyacrylamide). Contrast: Horizontal = Nucleic acids. Practice: Recall pore sizes, buffer systems (Laemmli discontinuous). PYQs often test SDS-PAGE specificity.
