Which of the following methods can be used to detect rubella infection in children –

Laboratory diagnosis Isolation of virus in cell cultures of throat samples, urine or other secretions. Normally, a maternal rubella antibody in the form of IgG is transferred to infants and is gradually last over a period of 6 months. Persistent beyond I year in an unvaccinated child suggests the diagnosis of congenital rubella. Presence of IgM antibodies is diagnostic. PCR for rubella RNA.