Studies on the efficiency of measles virus antigen production using VERO cell culture in a microcarrier system

1. A large amount of antigen is required to conduct seroepidemiologic surveys of measles. Thus, a process to obtain measles virus antigen using a bioreactor was standardized. 2. The virus was grown in a 3.7-1 culture of VERO cells using a Celligen cell culture system containing 2 mg/ml of microcarriers (cytodex I) at 37 degrees C and 60 rpm. The cultures infected with 0.5 m.o.i. of measles virus were harvested after the appearance of the cytopathic effect. The virus suspension was clarified and concentrated by ultracentrifugation. Intracellular and extracellular virus titers were determined by hemagglutination (HA) and by induction of a cytopathic effect in cell culture (TCID50). 3. Intracellular virus presented 5-7 x 10(6) TCID50/0.1 ml, HA activity per 50 microliters equal to 32, with a total HA activity of 4,480 HA units (HAU) and specific activity of 116 HAU/mg. In the concentrated supernatants, the HA titer of extracellular virus was 64, with a total HA activity of 1,024 HAU and a specific activity of 1,600 HAU/mg. 4. The antigen obtained was suitable for the detection of antibodies against measles virus in assays such as ELISA and DOT-ELISA (using 1 micrograms/well to ELISA and 2 micrograms/DOT). 5. The microcarrier system produced antigen sufficient for 26 ELISAs/ml compared to 5.7 ELISAs/ml obtained for the static culture system.

Estandarización de un sistema ultramicro ELISA indirecto para la determinación de anticuerpos totales al virus de sarampión / Standardization of an indirect ultramicro ELISA system for determining total antibodies to measles virus

Se desarrolló un sistema ultramicroELISA (UME) indirecto para la determminación de anticuerpos al virus del sarampión mediante la tecnología cubana de los sistemas ultramicroanalíticos (SUMA). Fueron procesados 448 monosueros procedentes del Sistema NAcional de Vigilancia Seroepidemiológica del Sarampión, simultáneamente por UME y por la técnica de inhibición de la hemaglutinación. Se compararon los resultados de ambos ensayos. Posteriormente se estudiaron 120 pares de sueros obtenidos de la misma fuente y procesados de forma similar. Los resultados demostraron la utilidad de dicho sistema inmunoenzimático para la realización del diagnóstico serológico y la validación positiva de la sustitución de las técnicas convencionales por esta nueva tecnología