What do the common transfer buffers do?

Three common transfer buffers for Western blotting include:

Towbin Buffer: Towbin buffer is the standard transfer buffer for western blots. It contains 25 mM Tris, 192 mM glycine, and 20% methanol (vol/vol), and is often used for tank (wet) or semi-dry blotting. Towbin buffer provides low ionic strength and low conductivity, which helps transfer proteins efficiently. SDS  in the range of 0.1–0.25% can be added to boost transfer efficiency.

Dunn Carbonate Buffer: Composed of 10 mM NaHCO₃ and 3 mM Na₂CO₃ (pH 9.9), Dunn carbonate buffer is useful for proteins that require a higher pH for effective transfer.

CAPS Buffer: Used in semi-dry western blotting, this transfer buffer contains 60 mM Tris and 40 mM CAPS (pH 11). It can enhance transfer efficiency by separating anode and cathode buffers, allowing for buffer customization at each electrode.