Isolation of total RNA from dermatophytes

We report a method for the preparation of total RNA from the anthropophilic dermatophyte Trichophyton rubrum. To generate large quantities of mycelia, the fungus was grown in liquid culture medium. The harvested mycelial mass was ground to a fine powder in liquid nitrogen and homogenized in guanidine isothiocyanate buffer followed by ultracentrifugation of the obtained suspension through a caesium chloride gradient. Analysis of the prepared RNA showed two prominent ribosomal RNA (rRNA) bands of about 3.36 and 1.82 kb. Northern blot hybridization with a beta-actin cDNA confirmed the high quality of the fungal mRNA. Successful isolation of RNA from two other dermatophyte species, namely Trichophyton mentagrophytes and Microsporum canis, demonstrated the general applicability of the described procedure.