Extraction and Analysis of A. mellifera Brain RNA

A. mellifera RNA was obtained from brains of forager bees collected into liquid nitrogen. The brains were dissected frozen on a precooled aluminium block (-80° C) surrounded by dry ice. Single brains were then homogenized in 320 µl RLT lysis buffer (QIAGEN RNeasy Mini Kit,
www.qiagen.com) using a rotor-stator homogenizer. Subsequently, total RNA was extracted via silica-matrix spin columns (QIAGEN RNeasy Mini Kit) including an on-column DNase I treatment (QIAGEN DNase I, RNase-free), both according to the manufacturer's instructions. For quality and integrity analysis, A. mellifera brain RNA (70 ng) was electrophoretically separated with an Agilent 2100 Bioanalyzer using an RNA 6000 Nano Chip Kit. When RNA was heat-denatured prior to separation (as recommended), RNA was incubated at 70° C for 2 min.