Phosphate buffered saline (pbs)

After S. cerevisiae was grown in YEPD for 4 h post-dilution, cells were counted in YEPD using Neubauer Improved (NI) hemocytometer (InCyto, Cheonan, Korea, #DHC-N01-2). A total of 700,000 cells were aliquoted into a 1.7 mL microfuge tube and heat shock stimulation was applied by placing the tube in an Eppendorf F1.5 Thermomixer set to 42 °C and 500 rpm for 20 min. At the end of the heat shock incubation, the microfuge tube containing the S. cerevisiae cells were placed on ice for 5 min. The cells were then washed once with ice-cold 1X PBS (Teknova, Hollister, CA, USA, #P0195) and 0.01% BSA (NEB, Ipswich, UK, #B9000Sm), henceforth referred to as PBS-BSA, quickly recounted, and brought to a concentration of 700,000 cells/mL in PBS-BSA. A total of 10 µL of RNase Inhibitor was added to 1 mL of yeast cells in PBS-BSA and mDrop-seq was performed as described below. The emulsion droplets were collected on ice to preserve the heat shock signal during the droplet encapsulation period.