Supplementary Figure S1. High-throughput phenotyping of cell-to-cell interactions in gel microdroplet pico-cultures

Pre-cultivation targeted FACS enrichment of aGMDs and abGMDs. (A) Only aGMDs and abGMDs containing algal/bacterial cells were first sorted by size by measuring forward scatter (FSC, x-axis at linear scale) versus side scatter (SSC, y-axis at logarithmic scale). (B) aGMDs and abGMDs were further analyzed by chlorophyll autofluorescence using a 650/50 nm filter (x-axis at logarithmic scale) versus 530/40 nm filter (y-axis at logarithmic scale), to select for GMDs containing algal/bacterial cells. (C) aGMDs and abGMDs were last sorted by measuring chlorophyll autofluorescence using a 650/50 nm filter (x-axis at logarithmic scale) versus side scatter (SSC, y-axis at logarithmic scale) and validated by microscopy to contain the desired single algal cell with 4 ± 1 bacterial cells.