Discover the Latest in Biomedical Research Innovation

The delta delta Ct method turns two Cq values per sample into a fold change in a minute of arithmetic. The two mistakes it hides take longer to spot: efficiency that is not quite 100%, which inflates your biggest results, and statistics run on fold changes instead of Cq values. This SOP runs from raw Cq to a fold change with a correct, asymmetric confidence interval.

If your treatment raises GAPDH by half, every target you normalize to it looks a third lower, even if nothing changed. Few labs check: studies use 1.2 reference genes on average, and only 15% test a panel first. This guide covers choosing candidates from different pathways, validating them with geNorm and NormFinder, and what MIQE 2.0 now asks you to report.

Cut your finger and the wound closes because skin cells crawl inward until they meet. That is cell migration, and the scratch assay is how labs measure it. A plain-language guide to what the experiment does, why it appears in cancer, wound healing and device research, and what changed when its two manual steps became mechanical.