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#RNA isolation

3 public questions tagged with this topic.

DNA & RNA isolation

Which is *not* used in RNA isolation?

RNA isolation requires potent RNase inhibitors and denaturants such as GITC which chaotropically inactivates RNases, and phenol-chloroform which partitions RNA into aqueous phase while denaturing proteins. Chloroform aids phase separation and removes lipids. SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is an analytical method for separating proteins by size based on SDS-denatured migration, not an extraction method for RNA. It is used post-extraction for protein analysis and would degrade RNA preparations. Thus SDS-PAGE has no role in RNA isolation workflow and is unrel

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

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DNA & RNA isolation

Oligo dT column binds to:

Oligo dT chromatography exploits the polyadenylation of eukaryotic mRNA. Mature mRNAs possess 3' poly-A tail of 150-250 adenine residues added post-transcriptionally, crucial for stability and translation. Oligo dT column contains short oligomers of deoxythymidine immobilized on resin. Under high salt conditions, adenines in poly-A tail form stable hydrogen bonds with thymines via A-T base pairing, retaining eukaryotic mRNA specifically. rRNA, tRNA, and non-polyadenylated RNAs lack poly-A tails and flow through. Elution at low salt disrupts hydrogen bonding and releases purified mRNA intact.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

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DNA & RNA isolation

GITC is primarily used in RNA isolation for:

GITC (guanidinium isothiocyanate) is a powerful chaotropic agent used in RNA isolation methods like TRIzol. It simultaneously lyses cells, denatures proteins, and inactivates RNases instantly by disrupting hydrogen bonding and hydrophobic interactions, unfolding secondary structures. RNases are extremely resilient and require strong denaturants; GITC at 4 M denatures them irreversibly, protecting RNA from degradation. It does not primarily digest proteins enzymatically, inhibit DNases selectively, or solubilize lipids only. Combined with phenol, it allows partitioning of intact RNA into aqueou

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details