Cytometry Part A: 'Mass-tag barcoding for multiplexed analysis of human synaptosomes and other anuclear events'

Mass-tag cell barcoding has increased the throughput, multiplexing, and robustness of
multiple cytometry approaches. Previously, we adapted mass cytometry for cells to
analyze synaptosome preparations (mass synaptometry or SynTOF), extending mass
cytometry to these smaller, anuclear particles. To improve throughput and individual
event resolution, we report here the application of palladium-based barcoding in human
synaptosomes. Up to 20 individual samples, each with a unique combinatorial barcode,
were pooled for labeling with an antibody cocktail. Our synaptosome protocol used six
palladium-based barcoding reagents, and in combination with sequential gating
increased the identification of presynaptic events approximately 4-fold. These same
parameters also efficiently resolved two other anuclear particles: human red blood cells
(RBCs) and platelets. The addition of palladium-based mass-tag barcoding to our
approach improves mass cytometry of synaptic particles.