RNeasy Stabilization and Total RNA Isolation System

The RNeasy System is designed for fast and efficient isolation of total RNA from a wide variety of samples. Different kits are tailored to suit different RNA purification needs. RNeasy Protect Kits provide immediate stabilization of RNA in the sample for accurate expression analysis. RNeasy sample preparation technology is fully licensed, allowing RNeasy purified nucleic acids to be used in any molecular assay or other downstream application without risk of patent infringement.

Features and benefits

Immediate RNA stabilization and protection in biological samples to ensure reliable gene-expression and gene-profiling data*
Convenient and safe stabilization and RNA isolation — no need for liquid nitrogen, dry ice, or hot phenol*†
Ready-to-use high-quality RNA in minutes
No phenol–chloroform extraction,† no CsCl gradients, no LiCl or ethanol precipitation
Excellent recovery of RNA from very small to large amounts of starting material

*	RNeasy Protect and RNeasy Protect Bacteria Kits only.
†	RNA prepared using phenol-extraction methods may contain contaminating phenol, which affects the A260/A280 ratio of the purified RNA due to absorbance of phenol at 270 and 275 nm (see Stulnig, T.M. and Amberger, A. [1994] Exposing contaminating phenol in nucleic acid preparations. BioTechniques 16, 403).

	RNeasy Kits
	Sample Source	Recommended RNeasy Kit

	Animal cells
	Small-to large-scale	RNeasy Mini, Midi, and Maxi Kits
	96-well format	RNeasy 96 Kit
	Automated, 96-well format	RNeasy 96 BioRobot Kit


	Animal tissues
	Small- to large-scale, with stabilization	RNeasy Protect Bacteria Mini and Midi Kits
	Small- to large-scale	RNeasy Mini, Midi, and Maxi Kits


	Bacteria
	Small- to large-scale, with stabilization	RNeasy Protect Bacteria Mini and Midi Kits
	Small- to large-scale	RNeasy Mini, Midi, and Maxi Kits


	Yeast	RNeasy Mini, Midi, and Maxi Kits


	Human whole blood, with stabilization	PAXgene Blood RNA System
	Human whole blood	QIAamp RNA Blood Mini Kit


	Plant cells or tissues	RNeasy Plant Mini Kit


	Filamentous fungi	RNeasy Plant Mini Kit


	In vitro transcripts and enzymatic reactions
	Small-to large-scale	RNeasy Mini, Midi, and Maxi Kits
	96-well format	RNeasy 96 Kit

Principle

Once a biological sample is harvested, its RNA becomes extremely unstable. Immediate stabilization of the RNA and preservation of the RNA expression pattern is a prerequisite for accurate gene-expression analysis. Gene induction or down-regulation triggered by sample manipulation must also be prevented. Immediate protection in tissue, with RNAlater RNA Stabilization Reagent, or in bacteria, with RNAprotect Bacteria Reagent, ensures that downstream analyses reflect the true expression profiles. These reagents quickly permeate the biological sample, stabilizing and protecting the RNA. Following stabilization, RNeasy technology simplifies total RNA isolation by combining the stringency of guanidine-isothiocyanate lysis with the speed and purity of silica-gel–membrane purification. There is no need for phenol/chloroform extraction, centrifugation through CsCl cushions, or precipitation with LiCl or alcohol.

Changes in mRNA Levels Using Traditional Methods

True RNA Profile with RNeasy Protect Kits

Procedure

Samples can be stabilized and stored in RNAlater RNA Stabilization Reagent, included in RNeasy Protect Kits, or RNAprotect Bacteria Reagent, included in RNeasy Protect Bacteria Kits (see flowchart). For RNA purification, samples 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-gel membrane. RNA binds, and all contaminants are efficiently washed away. Pure, concentrated RNA is eluted in water.

Applications

RNA purified with RNeasy technology has A260/A280 ratios of 1.9–2.1* and is ideal for use in all applications. Downstream applications include:

Northern, dot, and slot blotting
RT-PCR (see QIAGEN RT-PCR Systems Overview)
Quantitative, real-time RT-PCR (see Quantitect SYBR Green PCR and RT-PCR System)
Array analysis (see microarray Products)
Poly A+ RNA selection