Preservation of nasopharyngeal smears for fluorescent antibody detection of Bordetella pertussis.

Smears from throat and nasal washings seeded with Bordetella pertussis were either treated with aprotinin (a protease inhibitor) or fixed with 1 or 10% Formalin. These smears were stored at 23, 4, and -70 degrees C. Smears were removed and stained with a fluorescent antibody conjugate for B. pertussis at intervals during 22 days of storage. Results indicate that treatment of smears with 4 or 8 U of aprotinin per ml preserved fluorescent antibody staining qualities of B. pertussis for 22 days; fixation with either concentration of Formalin was unsatisfactory.