title: Retention of albino and brown phenotypes of Histoplasma capsulatum by liquid nitrogren refrigeration.
abstract: Pathogenic differences between albino (A) and brown (B) phenotypes of Histoplasma capsulatum for experimental animals, and serological differences between A- and B- derived histoplasmins or yeast-phase antigens, necessitate the retention of these phenotypes in culture for diagnoses and epidemiologic studies. Selected strains of A and B types were frozen in liquid nitrogen (LN) and stored for 6-9 months in the vapor phase of a LN refrigerator (-165 degrees C). The strains were tested by using Berliner's method for differentiation of these two phenotypes. The results have proved that the LN refrigeration can be used for long-term conservation to prevent the conversion of B type into the A type in vitro.
mesh_terms: D003116:Color; D005615:Freezing; D006658:Histoplasma / Q000166:cytology* / Q000276:immunology / Q000472:pathogenicity; D006659:Histoplasmin / Q000032:analysis; D009584:Nitrogen; D010641:Phenotype; D012034:Refrigeration
chemical_list: D006659:Histoplasmin; D009584:Nitrogen