Diana Rae Martin, Principal Scientist, ESR, is a leading New Zealand microbiologist who has an international reputation for her work on streptococcal diseases. Her early work defined the streptococcal opacity factor, a key feature of phenotypic typing methods, and her work challenged the premise of serotype-specific immunity. Dr Martin quickly recognised the power of new molecular techniques and led the development of streptococcal typing by restriction fragment length polymorphism using pulsed gel electrophoresis. This method is now used internationally. Recently, Dr Martin has found that the causative serogroup B strain of Neisseria meningitidis, the organism causing the epidemic of meningococcal meningitis in children in New Zealand, is the same as epidemic strains in The Netherlands. This is a significant breakthrough and she is working on vaccine development with international researchers.