Pepsin Solution for Antigen Exposure

Dissolve 0.75 g of pepsin in 30 mL of phosphate-buffered saline (0.1 m, pH 7.4) that has been warmed to 37°C. Separately, warm 240 mL of 0.1 n HCl to 37°C in a staining dish. Place both containers into the incubator at 37°C. Thirty seconds before the pepsin is needed, pour the 30 mL of pepsin solution into the 0.1 n HCl in the staining dish.

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