A Laser Capture Microdissection Protocol That Yields High Quality RNA from Fresh-frozen Mouse Bones

RNA yield and integrity are decisive for RNA analysis. However, it is often technically challenging to maintain RNA integrity throughout the entire laser capture microdissection (LCM) procedure. Since LCM studies work with low amounts of material, concerns about limited RNA yields are also important. Therefore, an LCM protocol was developed to obtain sufficient quantity of high-quality RNA for gene expression analysis in bone cells. The effect of staining protocol, thickness of cryosections, microdissected tissue quantity, RNA extraction kit, and LCM system used on RNA yield and integrity obtained from microdissected bone cells was evaluated. Eight-µm-thick frozen bone sections were made using an adhesive film and stained using a rapid protocol for a commercial LCM stain. The sample was sandwiched between a polyethylene terephthalate (PET) membrane and the adhesive film. An LCM system that uses gravity for sample collection and a column-based RNA extraction method were used to obtain high quality RNAs of sufficient yield. The current study focusses on mouse femur sections. However, the LCM protocol reported here can be used to study in situ gene expression in cells of any hard tissue in both physiological conditions and disease processes.