Sodium Dodecyl Sulphate-Sodium Chloride Extraction of Penicillium stolonwerum Mycelium for Viral Double-stranded RNA

Incubation of mycelia of a virus-containing strain of Penicillium stoloniferum in a I % sodium dodecyl sulphate-4 % sodium chloride (SDS-NaCl) solution liberated protein and deoxyribonucleic acid within the first hours, whereas ribonucleic acid (RNA) release continued through an extended period. Although transfer RNA (tRNA) was readily solubilized by the treatment, viral doublestranded RNA (dsRNA) was not detected in the extracellular lysate during the initial 6 h of incubation. After 24 h of treatment, mechanical disruption of the mycelia liberated some dsRNA; this procedure demonstrated the incomplete solubilization of viral nucleic acid in SDS-NaCl. Scanning electron micrographs of mycelium treated with a salt-detergent mixture showed a progressive reduction in structural integrity of fungal hyphae. However, hyphal tips appeared to remain morphologically intact during incubation.