RNA Purification: Common Pitfalls and Fixes

Team Dynamic Matrices 

Most RNA purification failures trace back to a handful of recurring issues. Knowing them in advance saves a considerable amount of repeated troubleshooting later, especially when results look subtly off rather than obviously failed.

Degradation During Extraction

RNases are everywhere, including on skin and standard lab surfaces. Working fast, keeping samples cold throughout, and using RNase-free reagents and consumables at every step, not just during the formal extraction step itself, are the basic but frequently skipped precautions.

Genomic DNA Contamination

This is especially relevant for downstream RT-qPCR, where contaminating genomic DNA can be mistaken for amplified product and inflate apparent expression levels. A DNase digestion step, even when listed as "optional" in a kit's protocol, is rarely worth skipping if downstream quantification accuracy matters.

Low Yield from Difficult Sample Types

Tissues with naturally high RNase content, such as pancreas, or samples with very low cell numbers need extraction chemistry specifically matched to that challenge. Generic kits optimized primarily for cultured cell lines often underperform noticeably on these harder sample types.

Inconsistent A260/A280 Ratios

This is often a sign of protein or phenol carryover from the extraction process itself, not necessarily a sign that the RNA quality is genuinely poor. Re-extracting with an added wash step usually resolves it, and that's worth trying before concluding the underlying sample is unusable.