Carbonate-bicarbonate coating buffer (pH 9.6, ELISA) recipe

Base: 1 L · pH 9.6 (set by the salt ratio) · Updated 2026-10-01

Coats capture antibody or antigen onto ELISA plates: 0.05 M carbonate-bicarbonate, pH 9.6.

🧮 Volume calculator
ComponentAmount Final concentration (1X)
Na₂CO₃ (anhydrous)159 mg15 mM
NaHCO₃293 mg35 mM
Water (distilled)to final volume

Steps

  1. Dissolve in about 80% of the final volume of water.
  2. Check pH 9.6 (usually no adjustment needed).
  3. Bring to the final volume with water.
  4. Store at 4 °C and use within 1–2 weeks.

Good to know

FAQ

What if it sits open for long?

It absorbs CO₂ and the pH drops — keep it capped.

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.