Do it yourself! – Initial experiences with self-synthesized CsTFA for RNA-SIP analyses

Cesium trifluoroacetate (CsTFA) is a gradient medium for isopycnic centrifugation in RNA-based Stable Isotope Probing (RNA-SIP), an important means to link the structure and function of microbial communities. We report a protocol to easily synthesize CsTFA from cesium carbonate (Cs2CO3) and trifluoroacetic acid (TFA) and show that self-synthesized CsTFA performs similarly to commercial CsTFA in the separation of isotopically labelled and unlabelled bacterial RNA. •RNA-SIP is an elegant technique to link the structure and function of microbial communities.•Concentrated CsTFA solution for RNA-SIP analyses is currently no longer commercially available.•CsTFA can easily be synthesized from Cs2CO3 and TFA.•s-CsTFA performs similar to c-CsTFA in the separation of isotopically labelled and unlabelled bacterial RNA.