| differentiation of vaccine strains and georgia field isolates of infectious laryngotracheitis virus by their restriction endonuclease fragment patterns. | seven restriction endonucleases (res) were used to cleave the dna from seven vaccine strains of infectious laryngotracheitis (ilt) virus and from six georgia field isolates of ilt virus. after electrophoresis of the resulting re fragments, the patterns were compared in order to differentiate strains of ilt virus. the six chicken-embryo-origin (ceo) vaccines were identical with each re, but the tissue-culture-origin (tco) vaccine strain differed from the ceo vaccines using five of the res. four o ... | 1990 | 2173534 |