Epidemiological-serological investigations of yaws. Freezing and transport of sera at--150 to---196 degree in liquid nitrogen.
D001793:Blood Preservation / Q000295:instrumentation*; D005615:Freezing; D009584:Nitrogen; D012034:Refrigeration / Q000295:instrumentation; D014944:World Health Organization; D015001:Yaws / Q000453:epidemiology* / Q000276:immunology
D009584:Nitrogen