Ammonium Sulfate, Saturated

• 1. Add 761 g of ammonium sulfate (for research grade antibodies, use Sigma-Aldrich catalog no. A2939 or equivalent) to 1 L of appropriate grade H₂O (∼4.1 m).

• 2. Dissolve with stirring and gentle heating.

• 3. 3Cool to room temperature and adjust the pH to 7 (with NH₄OH or an acid such as HCl).

• 4. If excess is to be stored, sterilize the solution by filtering through a 0.2-µm filter and store at 4°C.

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