Anti-SYT1 (phospho S309) Antibody - Identical to Abcam (ab194799)

This polyclonal antibody from Antibodies.com is raised in rabbit and selectively recognizes human Synaptotagmin-1 (SYT1) only when phosphorylated at serine 309. SYT1 functions as the principal calcium sensor at presynaptic active zones, coupling calcium influx to synaptic vesicle fusion during evoked neurotransmitter release, and modification at the S309 residue contributes to modulating this release machinery. The reagent is supplied unconjugated as 200 µL of polyclonal IgG, prepared for immunofluorescence workflows that map phospho-SYT1 distribution in human, mouse, and rat neural tissue. Typical applications include probing primary neuron cultures, fixed brain cryosections, and differentiated neuronal cell lines, where the rabbit IgG isotype supports secondary detection with standard anti-rabbit fluorophore conjugates. By targeting a defined phospho-site rather than total SYT1, this reagent supports investigation of activity-dependent regulation of presynaptic release, comparing basal versus stimulated states of synaptic terminals, and tracking changes associated with synaptic plasticity in neuroscience and cell signaling research.