title: The stability of human, bovine and avian tuberculin purified protein derivative (PPD).
abstract: BACKGROUND
  Guidelines recommend storing tuberculin purified protein derivative (PPD) refrigerated. However, especially in developing countries, maintaining the product refrigerated under field conditions can be difficult, limiting its use. Here we determine the effect of prolonged exposure to high temperatures on the potency of human, bovine and avian tuberculin PPD.
  
  
  METHODS
  Human, bovine and avian tuberculin PPD were stored for several weeks exposed to temperatures ranging from 37º to 100ºC. The potency was evaluated in vivo, in sensitized or naturally infected animals.
  
  
  RESULTS
  Most test situations didn't affect the biological activity of the tuberculin PPDs and only very long and extreme incubations (several days at 100 °C) compromised the potency.
  
  
  CONCLUSIONS
  Tuberculin PPD is very stable and can be stored or transported for long periods without refrigeration.
authors: Laboratorio de Tuberculosis, Instituto de Biomedicina, Universidad Central de Venezuela, Caracas, Venezuela.mailismaes@gmail.com
authors: Mailis
authors: M
authors: Maes
authors: José Francisco
authors: JF
authors: Giménez
authors: Adriana
authors: A
authors: D'Alessandro
authors: Jacobus H
authors: JH
authors: De Waard
mesh_terms: D000818:Animals; D001717:Birds; D002417:Cattle; D019411:Clinical Laboratory Techniques / Q000592:standards*; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods; D006168:Guinea Pigs; D006801:Humans; D055550:Protein Stability; D013696:Temperature; D013997:Time Factors; D014373:Tuberculin / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D014373:Tuberculin