“…To incorporate cellular phenotype reporters and cell‐type barcoding in parallel with antibody panels, small molecules bearing heavy elements were pursued for MC and IMC™ applications. This led to the development of numerous scaffolds, such as iridium and rhodium organometallic intercalators for cell enumeration, [29] bifunctional palladium and indium chelates for cell barcoding, [30,31] cisplatin for live/dead cell staining, [32] osmium and ruthenium tetroxide salts for cell barcoding and cell size discrimination, [33] bulky alkyl‐derivatives of chelators for staining bacteria [34] and eukaryotic organelles, [58] 5‐iodo‐2‐deoxyuridine (IdU) for cell cycle analysis, [35] and a collection of organotelluriums for a variety of applications including live cell barcoding in heterogenous suspensions [36] and organoids, [37] amplification of low abundance antigens in IMC™; [38] and monitoring biological states such as hypoxia, [39,40] senescence associated β‐galactosidase activity, [41] and protein synthesis turnover [42] . With the updated collection of MC and IMC™ reagents, 40–50 parameters can now be measured simultaneously from individual cells.…”