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

This rabbit polyclonal IgG reagent from Antibodies.com specifically recognizes Synaptotagmin-1 (SYT1) only when serine 309 is phosphorylated, a post-translational mark dynamically regulated by CaMKII and PKC at presynaptic terminals. Synaptotagmin-1 is the principal vesicular calcium sensor (~47 kDa, UniProt P21579) that drives fast, synchronous neurotransmitter release, and phosphorylation at S309 tunes its coupling to the SNARE fusion machinery during synaptic plasticity. Researchers apply this phospho-state-selective antibody in immunofluorescence workflows to visualize the kinase-tagged SYT1 pool in neurons, mapping how presynaptic activity reshapes the release trigger. Cross-reactivity with mouse and rat SYT1 orthologs (S308/309) enables side-by-side comparison across rodent models and human tissue, supporting studies on short-term plasticity, PKC-dependent potentiation, and calcium-driven exocytosis. The unconjugated format pairs with fluorophore-conjugated secondaries for multichannel imaging, and the 100 µl vial is stored at -20 °C with protection from repeated freeze-thaw cycles to preserve phospho-epitope sensitivity.