RNeasy Protect Mini Kit

The RNA-stabilizing properties of RNAprotect Tissue Reagent prevent gene induction or down-regulation triggered by sample manipulation, and allow purification of high-quality RNA (see figure "Prevention of degradation of mRNA in tissues"). In addition, RNeasy purified RNA from RNAprotect stabilized samples remains intact following storage of tissue samples under a wide variety of conditions (see figure "Stable RNA in tissues"). A range of tissue types can be processed with the RNeasy Protect Mini Kit (see table).

RNA purified with RNeasy technology has A₂₆₀/A₂₈₀ ratios of 1.9–2.1 (measured in 10 mM Tris·Cl, pH 7.5). Since the RNeasy procedure enriches for RNA species >200 nt, RNA yield does not include 5S rRNA, tRNAs, or other low-molecular-weight RNAs.

The RNeasy Protect system provides a complete RNA protection and isolation solution, from sample harvesting to pure RNA, in one kit. Proven RNeasy silica-membrane technology in spin-column format, combined with the RNA-stabilizing properties of RNAprotect Tissue Reagent, allows purification of high-quality, intact RNA. Once a biological sample is harvested, its RNA becomes extremely unstable (see figure "Changes in mRNA levels"). The innovative, aqueous RNAprotect Tissue Reagent quickly permeates tissues, stabilizing and protecting the RNA expression pattern. Samples can be archived without risk of RNA degradation, even after multiple freeze–thaw cycles. Following stabilization, RNeasy technology simplifies total RNA isolation by combining the stringency of guanidine-isothiocyanate lysis with the speed and purity of silica-membrane purification (see figure "RNeasy Mini spin column").

Samples can be stabilized and stored in RNAprotect Tissue Reagent, included in RNeasy Protect Kits. For RNA purification, samples (0.5–30 mg tissue) are first lysed and then homogenized. Ethanol is added to the lysate to provide ideal binding conditions. The lysate is then loaded onto the RNeasy silica membrane (binding capacity up to 100 µg RNA). RNA binds, and all contaminants are efficiently washed away. Pure, concentrated RNA is eluted in 30–100 µl water (see flowchart "RNeasy Protect Mini procedure"). RNA purification can be automated on the QIAcube.

RNA purified with RNeasy technology is ideal for use in all applications. Downstream applications include:

• Northern, dot, and slot blotting
• End-point RT-PCR
• Quantitative, real-time RT-PCR
• Array analysis
• Poly A+ RNA selection