Fig. 1

Sort-seq for massively parallel measure of protein variability. a Eight codons on the 5′ end of GFP are synonymously mutated. b Experimental procedure for massively parallel measurement of gene expression variation using Sort-seq. The plasmid library containing the synonymously mutated GFP was transformed to E. coli to create a pooled library. Fluorescence activated cell sorting (FACS) is used to sort the library into 20 bins based on GFP fluorescence. Plasmids are isolated from the sorted cells in each bin and are subjected to high-throughput sequencing. The number of reads for each unique GFP sequence is mapped back to each bin that represents a corresponding fluorescence intensity. Protein variability for each GFP sequence is calculated from a fitted Gamma distribution