Table S1.

Screening summary

Library ID	Library size, in millions	Valid sequence reads*	Minimum count/enrichment†	Total hits	Resynthesized compounds
DL5c_260	96	1,011,059	≥5/475-fold	39	4
DL7a_623	85	982,396	≥5/433-fold	175	8
DL11a_629	9	866,825	≥25/260-fold	180	4

^*Each full-length sequence read was matched against a sequence database representing all possible library encoding combinations to translate each DNA molecule into its corresponding set of chemical identifiers. Only those reads for which all encoding elements could be conclusively identified were considered valid (excluding reads that represented PCR-derived duplicates).

^†“Minimum Count/Enrichment” is an arbitrary cutoff used to increase the ratio of signal to noise in the postselection dataset by filtering out compounds that were observed infrequently and generally shared no structural similarities. “Count” represents the number of valid sequence reads observed for a given compound. “Enrichment” represents the calculated change in frequency from baseline for each compound, where baseline was assumed to equal 1/“library size.”