366, 2,607, and 26. Those are the number of copies per cell of three different human genes, ACTB, GAPDH, and BRCA1, used to test something most RNA workflows take for granted: that you actually know how many cells your extract came from.

Optical density and fluorescent dye methods for estimating RNA quantity struggle with low cell counts and unpurified lysates. RNAGEM Tissue offers a different route. Because it co-extracts genomic DNA alongside RNA in consistent, linear proportions, the DNA in the same lysate can be used to estimate cell number by qPCR, without a separate RT-qPCR step.

Testing across a range of 10 to 10,000 HeLa cells showed linear extraction yields for both DNA and RNA, including for BRCA1, a low-copy gene at just 26 copies per cell, suggesting the method holds even when the target transcript is scarce.

Sample normalisation matters most exactly when it is hardest to do well: low cell counts, small volumes, high-throughput plate formats. A simpler qPCR-based estimate, rather than a full RT-qPCR, is a meaningful saving at scale.