Single Strand Conformation Polymorphism analysis of PCRamplified rDNA to differentiate medically important Aspergillus Species

Background: aspergillus species are associated with allergic bronchopulmonary disease, mycotic keratitis, otomycosis, nasalsinusitis and invasive infection. in this study, we developed a pcr-single strand confomational polymorphism methodto identify the most common aspergillus species and we showed some advantages of this method comparing a pcr-restrictionfragment length polymorphism with our designed restriction enzyme.methods: we selected its2, as a short fragment within the rdna region (length size: 330 bp) to be amplified as small sizepcr product. we mixed 5 ml of the pcr product with an equal volume of loading buffer and followed by incubation for 5min at 95º c and quenching in an ice bath. the mixture was applied to a 6%-12% gradient poly acryl amide gel to run in avertical electrophoresis, then gel was stained with ethidium bromide and silver nitrate which followed by an ethidium bromidestaining.results: our results of restriction digestion showed a fine identification of 7 tested aspergillus species during 5-6 hours afteran overnight mycelial growth. as our results some of tested aspergillus species: a. nidulans, a. fisheri, a. quadricincta,(a. fumigatus and a. niger) as a group and (a. flavus, a. tereus and a. ochraceus) as another group, can be discriminated.moreover sscp analysis enabled us to identify above aspergillus species within 8-12 h after an over night growth withoutusing an expensive restriction enzyme.conclusion: it is concluded that single strand conformational polymorphism is a simple and rapid method for identificationof some medically important aspergillus.