Comparison of methods of production of farmer's lung antigens.

The extracellular growth products of Micropolyspora faeni, Thermoactinomyces vulgaris and Thermoactinomyces candidus were prepared by three methods; (1) double dialysis; (2) growth in tryptone soya broth (TSB) and (3) synthetic broth (AOAC). It was found that double dialysis was superior to growth in TSB or AOAC for the production of M. faeni antigens, as determined by immunoblot. Double dialysis, TSB and AOAC were similar for antigens of T. vulgaris and T. candidus. Both organisms showed bands of the same mobility on immunoblot and also produced lines of identity on double diffusion.