Rat hippocampal neurons were incubated live at 37°C & 5% CO₂ in full Neurobasal medium with 100 nM sdAb anti-Syt1 Luminal Domain pHluorin fusion (Cat. No. N4842, dilution 1:50) for 30 min. After washing and PFA fixation, cells were counterstained with FluoTag®-X2 anti-Syt1 Cytosolic Domain (A51) directly conjugated to Atto643 (Cat. No. N4302-At643-L, dilution 1:500). Images were acquired using a 60× oil-immersion objective on an epifluorescence microscope. The sdAb anti-Syt1 Luminal Domain pHluorin fusion labels only active/recycling synapses (A, green), whereas FluoTag®-X2 anti-Syt1 Cytosolic Domain (A51) labels the total Syt1 pool (B, magenta). Arrowheads indicate expected colocalization at some synapses. DAPI is displayed in grey on the merged right panel (C). Scale bar: 20 µm.

sdAb anti-Syt1 Luminal Domain pHluorin fusion

Name: sdAb anti-Syt1 Luminal Domain pHluorin fusion
SKU: N4842
Availability: InStock

Cat No: N4842 Category: Primary sdAbs

290,00 €

A single-domain antibody recognizing the luminal/extracellular domain of Synaptotagmin 1 (Syt1) fused to superecliptic pHluorin. This pH-sensitive reagent is intended exclusively for use in living neurons to label active synapses that recycle Syt1 following synaptic vesicle fusion.

sdAb anti-Syt1 Luminal Domain pHluorin fusion combines a single-domain antibody (sdAb) targeting the luminal/extracellular domain of Synaptotagmin 1 (Syt1) with superecliptic pHluorin, an enhanced pH-sensitive GFP variant with improved fluorescence properties, used for live-cell imaging of synaptic vesicle cycling.

Synaptotagmin 1 belongs to the synaptotagmin protein family, which in mammals consists of 17 single-pass transmembrane proteins containing two intracellular calcium-binding domains. Syt1 is enriched at presynaptic boutons on axon terminals and is associated with synaptic vesicles, where it plays a role in calcium-triggered synaptic vesicle fusion and neurotransmitter release.

Our sdAb anti-Syt1 Luminal Domain binds specifically to the mouse and rat Syt1 luminal/extracellular epitope KEDAFSKLKQKF, and the human epitope KEDAFSKLKEKF (other species not tested).

Fusion of this nanobody to superecliptic pHluorin sensor enables real-time tracking of Synaptic Vesicles (SV) fusion events in live cells. pHluorin fluorescence is quenched at pH 5.5 inside the synaptic vesicle lumen and increases upon vesicle fusion with the plasma membrane, when it encounters the neutral pH of the extracellular milieu. This provides a sensitive optical readout of synaptic vesicle exocytosis and active synapses.

Real-time tracking of Synaptic Vesicles (SV) fusion events in live cells using sdAb anti-Syt1 Luminal Domain pHluorin fusion (NanoTag Biotechnologies, N4842)

Important Note: The reagent is intended exclusively for use in live-cell systems to label active synapses. Aldehyde-based fixatives (including paraformaldehyde, glutaraldehyde, glyoxal, or related compounds) modify lysines within the target epitope, thereby significantly impairing Syt1 recognition.

Comprehensive characterization data for this sdAb anti-Syt1 Luminal Domain have been published here, where it is referred to as NbLumSyt1.

sdAb anti-Syt1 Luminal Domain (clone #1F12) binds to the extracellular/luminal domain of Syt1 in non-fixed samples. We also offer reagents based on sdAbs anti-Syt1 Cytosolic Domain (clones #A51 and #7D5), including labeled sdAbs, FluoTags^®-X2, and recombinant heavy-chain antibodies (rHcAbs). These reagents specifically recognize the cytosolic portion of Syt1 in fixed and non-fixed samples, thereby enabling detection of the total Syt1 pool. View the reagents targeting the Syt1 cytosolic domain here.

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