Detecting a synapse rather than a protein: why a psd95 antibody and a psd-95 antibody name the same scaffold whose signal is punctate and only meaningful as apposed puncta, what a homer1 antibody, a gephyrin antibody and a glua1 antibody add on the postsynaptic side and how an mglur5 antibody differs as a receptor, where a snap25 antibody, a syntaxin 6 antibody, a synapsin i antibody and a synapsin 1 antibody mark the presynaptic terminal, how a vglut1 antibody, a vgat antibody and a vacht antibody assign a transmitter identity that a scaffold marker cannot, what a gad1 antibody, a gad67 antibody, gad antibodies generally, a th antibody, a dbh antibody, an acetylcholinesterase antibody, a serotonin antibody, an npy antibody, a cck antibody, a crh antibody and a somatostatin antibody report about transmitter synthesis and content, and why a trkb antibody, a chrm3 antibody, a trpv1 antibody, an nav1.7 antibody, an nav1.8 antibody, a piezo1 antibody, a piezo2 antibody, a vgcc antibody, an orai1 antibody and a stim1 antibody are membrane targets that need their own extraction

Measuring synapses and transmitters

1. Score apposition, not puncta. Count pairs where a presynaptic and a postsynaptic marker are adjacent within the resolution limit. Counting one marker alone measures protein clusters, some of which are not synapses.
2. Fix for the compartment. Synaptic scaffolds and membrane receptors have different fixation optima, and a protocol that preserves one can destroy the other. Where both are needed, test the compromise on control tissue first.
3. Extract membrane targets deliberately. Channels and receptors are multipass membrane proteins that stay in the pellet with standard lysis and aggregate when boiled. Use a membrane protocol and follow the supplier's loading advice.
4. Separate transmitter identity from synapse number. Vesicular transporters assign the transmitter; scaffolds count contacts. Reporting a change in one as a change in the other is a frequent overreach.
5. Control the resolution claim. Apposition at the diffraction limit is suggestive rather than conclusive. Where the claim depends on it, use a super resolution method or an orthogonal measurement such as electrophysiology.

Resolution bounds the claim

At conventional light resolution, two puncta counted as apposed are within a distance that contains many non synaptic arrangements. That does not make the measurement useless, and it does mean the claim should be framed as putative contacts rather than synapses.

Where the number is central to a conclusion, add a method with better resolution or a functional measurement. Two independent lines make the claim durable.

Membrane targets are a different technique

Receptors, channels and transporters in this list share a problem with every other multipass membrane protein: poor solubilisation, aggregation on heating and epitopes that depend on conformation.

Treat them as a separate protocol within the same study, and validate each reagent on a positive control tissue before using it on the experimental material.

Common questions

Is a punctum a synapse?

Not necessarily. Scaffold and vesicle proteins form clusters that are not all synaptic. Apposition of pre and postsynaptic markers is the standard evidence, and even that is limited by resolution.

Why can I not detect my receptor on a blot?

Because it stayed in the pellet or aggregated on heating. Multipass membrane proteins need a membrane extraction protocol and usually gentler denaturation than a standard sample.

Which marker assigns transmitter identity?

The vesicular transporter, because it determines what the terminal releases. Synthetic enzymes are informative and less definitive, since the enzyme can be present where the transporter is not.

Browse by service class

• Compare Gene synthesis on advertised prices