Quantitate miRNA from a Few Drops of Mouse Blood
TaqMan® MicroRNA Assays
While inbred mouse models have been created for most human genetic disorders, including cancer and neurological diseases, blood samples from these mice have not been widely used in biomarker discovery studies. Two major obstacles are ex vivo changes in RNA expression levels introduced during collection, storage, and transport of blood, and the lack of reliable extraction methods with sufficient yields of high-quality RNA. Moreover, mice typically are sacrificed to obtain sufficient blood RNA for analysis, which does not allow for time course studies. This article describes how the Mouse RiboPure™-Blood Kit overcomes all of these issues. This kit can be used to isolate high-quality total RNA, including miRNA, from tail vein bleeds in time course studies. MicroRNA can then be quantitated using TaqMan® MicroRNA Assays.
The Mouse RiboPure-Blood RNA Isolation Kit is designed to recover total RNA—and optionally miRNA—directly from mouse or rat blood in ~35 minutes. The standard sample volume is 0.25–0.5 mL per reaction (e.g., mouse blood collected through cardiac puncture); however, minor procedural modifications included in the Instruction Manual allow smaller volumes to be used (e.g., mouse blood collected from the tail vein or an orbital bleed).
The kit includes microfuge tubes pre-loaded with RNAlater® Tissue Collection:RNA Stabilization Solution, which prevents RNA degradation and preserves RNA profiles within samples at room temperature for up to 3 days or at –20ºC for long term. Typically, 30–55 µg of total RNA (containing miRNA) is obtained from 0.5 mL mouse blood. Yields from rat blood are more variable, generally 18–40 µg from 0.5 mL blood.