Parameters used to determine the number of ribosomes translating MLV FL RNA. (A) Illustration of different intensities of fluorescence of a single ribosome depending on its position on FL RNA. Lengths of Gag-24ST domains are given in amino acids. Created with https://BioRender.com. (B) KIF1C calibrator fused to 24XST at C terminus. N is the length of the protein counting from ST region and n corresponds to the length of 24XST in amino acids.