Reagents for barcoding were prepared as previously described.15 (link) Two molar equivalents of maleimido-mono-amide-DOTA (Macrocyclics, Inc., Dallas, TX) were added to palladium 102, 104,105, 106, 108, and 110 solutions in 20 mM ammonium acetate, pH 6.0. Solutions were immediately lyophilized, and solids were dissolved in dimethyl sulfoxide (DMSO) to 10 mM for storage at −20 °C. Each well of a barcoding plate contained a distinct combination of three palladium isotopes at 200 nM in DMSO.
After thawing and red blood cell lysis in a hypotonic buffer, cells were barcoded as previously described.16 (link) Briefly, cells were transferred into a deep-well block and washed once with cell staining media (CSM, PBS with 0.5% BSA, 0.02% NaN3), once with PBS, and once with 0.02% saponin in PBS. The barcoding plate was thawed, and each well of barcode reagent was diluted in 1 mL 0.02% saponin in PBS. Diluted barcode reagent was transferred to cells, and samples were incubated at room temperature for 15 minutes, washed twice with CSM, and then pooled for staining.
After thawing and red blood cell lysis in a hypotonic buffer, cells were barcoded as previously described.16 (link) Briefly, cells were transferred into a deep-well block and washed once with cell staining media (CSM, PBS with 0.5% BSA, 0.02% NaN3), once with PBS, and once with 0.02% saponin in PBS. The barcoding plate was thawed, and each well of barcode reagent was diluted in 1 mL 0.02% saponin in PBS. Diluted barcode reagent was transferred to cells, and samples were incubated at room temperature for 15 minutes, washed twice with CSM, and then pooled for staining.
