Viruses require living cells and can be adapted to growth in eggs, which serve as suitable hosts for virus isolation, identification and production of vaccines. While antibodies are not produced by the chicken embryo, eggs should be obtained from an unvaccinated flock.

The different routes of inoculation are discussed and illustrated with a number of figures and the preparation, methods, labelling and sealing of eggs are detailed. These routes include inter alia the chorio-allantoic membrane, yolk sac, and intravenous routes.  Absolute sterility throughout is emphasized.

The chorio-allantoic membrane (CAM) route is useful as it supports the growth of many viruses. The requirements, methods and harvesting of materials are explained and illustrated. The intravenous and yolk sac routes are similarly explained.

The advantages, disadvantages, routes used and factors influencing the outcome of inoculation are discussed. All viruses of veterinary importance which grow in eggs are tabulated according to the disease caused, age of the embryos, routes of inoculation, incubation temperatures and outcomes of infection.

Preparation of a dilution series for egg fluids is described. This applies both to re-inoculation of additional eggs or testing for the presence of viruses. Red blood cells used in haemagglutination and haemagglutination inhibition tests are mainly obtained from guinea pigs or chickens, and the collection of blood from chickens and its preparation and the procedures for HA/HI tests are provided.