Flow cytometry is a powerful way to characterize protein expression at the single cell level, but new techniques are now using flow cytometry to measure RNA expression within individual cells. The PrimeFlow RNA assay is a method for measuring RNA in cells that is based on the fluorescent in situ hybridization technique (FISH) in which sequence-specific oligonucleotide probes are used together with DNA and fluorescent labels to specifically detect and amplify the signal for a specific RNA target. Consider these key features of PrimeFlow as you decide if it would be a valuable addition to your cell analysis toolkit.

1. Simultaneous analysis of protein and RNA expression. PrimeFlow RNA assays can be combined with traditional flow cytometry staining panels that measure expression of target proteins. PrimeFlow and conventional biomarker detection can be performed simultaneously if the appropriate fluorochromes are compatible with flow cytometer configurations, and spectral overlap is avoided. Protein and RNA expression can be measured at different time points in individual cells to provide insight into gene expression heterogeneity and kinetics.
2. Many different types of RNA can be targeted. Up to four different RNA targets can be measured in a single PrimeFlow assay. This is not limited to RNA transcripts, as noncoding RNA, viral RNA or even microRNA can be measured if the appropriate probes are used.
3. Superior to traditional FISH techniques. PrimeFlow assays are superior to traditional FISH assays, which have been limited by having high background and lower sensitivity due to poor signal amplification and nonspecific binding.

In this era of genomics and proteomics, the PrimeFlow assay is a critical tool for validating targets of interest and identifying variations in RNA and protein expression that affect cell functions. Consider working with a flow cytometry expert if you want to incorporate this assay into your next flow cytometry panel.