Citrate buffer pH 6.0 (antigen retrieval) recipe

Base: 1 L · pH 6.0 (adjust with 1 N HCl) · Updated 2026-09-30

Used for heat-induced epitope retrieval (HIER) to unmask formalin-fixed antigens in paraffin IHC. 10 mM sodium citrate, 0.05% Tween-20, pH 6.0.

🧮 Volume calculator
ComponentAmount Final concentration (1X)
Trisodium citrate dihydrate2.94 g10 mM
Tween-20500 µL0.05%
Water (distilled)to final volume

Steps

  1. Dissolve sodium citrate in about 900 mL of water.
  2. Adjust to pH 6.0 with 1 N HCl.
  3. Add Tween-20 and make up to 1 L.
  4. Store 3 months at room temperature, longer at 4 °C.

Good to know

FAQ

How long should I heat it?

Typically 10–20 min at 95–100 °C, then 20 min cooling at room temperature; microwaves, pressure cookers and water baths are all used.

This is a widely used standard composition. Amounts depend on the hydrate form and purity of your reagents — check the formula weight (FW) on the bottle and follow your institution's safety rules and the manufacturers' instructions.