Alternaria alternata is one of the most important fungal species involved in allergy. 

In a recent study Ibarrolla et al (Ann Allergy Asthma Immunol. 2004;93:589-593) describes the characterisation of the Alt a1 profile in Alternaria alternata cultures. The allergenic production profile was determined using both 2-site specific antibodies, immunoblotting and potency assays. The release of Alt a1 was also studied using electron microscopy. The investigation shows that the measurement of Alt a1, the major allergen in A. alternata, gives a good estimate of the total allergenic potency and that Alt a1 is predominantly excreted into the culture medium.