An improved method for high-quality RNA isolation from needles of adult maritime pine trees

Abstract

When conventional RNA isolation methods optimized for pine seedlings are applied to needles of adult pine trees, poor-quality RNA results. Here we describe a modified procedure to isolate high-quality RNA from needles of 30-year-old maritime pines, exhibiting high levels of phenolics, polysaccharides, and RNases. Major changes are the inclusion of proteinase K in the extraction medium followed by incubation at 42°C. Integrity and purity were evaluated by using denaturing gel electrophoresis and spectrophotometry (A260/A230 and A260/A280). The total RNA could be successfully used for poly(A)+-RNA isolation and cDNA library construction.