1. Ehrlich, P. The Collected Papers of Paul Ehrlich Vol. 3, 59 (Pergamon, London, 1960).
2. Keating, P. & Cambrosio, A. J. Hist. Biol. 27, 449–479 (1994).
3. Obermeyer, F. & Pick, E.P. Wien. klin. Wochenschr 19, 327–334 (1906); Pick, E.P. Biochimie der Antigene in Handbuch der pathogenen Mikroorganismen 2nd edn. Part I 685–868 (Fischer, Jena, 1912).
4. Further testimony to the rapid expansion of interest in these techniques is provided by Immunocytochemistry: Practical Applications in Pathology and Biology (eds. Polak, J.M. & Van Noorden, S.) (J. Wright, Bristol, 1983). In just 3 years between the first and second editions (1983–1986), the size increased from 396 to 703 pages.
5. Landsteiner, K. & Lampl, H.Z. Immunitätsforsch 26, 258–276; 293–304 (1917); also Landsteiner's magnum opus The Specificity of Serological Reactions (Dover, New York, 1962). This is a reprint of the second edition (Harvard University Press, Cambridge, 1945).