We use the following primers, developed by Zoller et al. (1999), to amplify and sequence the mitochondrial small subunit for phylogenetic analyses of lichenized ascomycetes:
Zoller, S., C. Scheidegger, & C. Sperisen. 1999. PCR primers for the amplification of mitochondrial small subunit ribosomal DNA of lichen-forming ascomycetes. Lichenologist 31(5):511-516.