Also called trifluoroacetic acid · trifluoroacetate · TFA counterion
Trifluoroacetic acid (TFA) is the cleavage reagent used in Fmoc SPPS; it remains as a counterion (trifluoroacetate) in the lyophilized product unless actively removed. Most research peptides are TFA salts by default. The TFA content is not biologically active but affects the net peptide mass and purity calculations.
Research use only. This definition is an educational reference, not medical advice or dosing guidance.