The NucleoSpin TriPrep kit allows you to isolate RNA, DNA, and protein simultaneously from one lysate, allowing sensitive gene expression analysis for small, rare, or precious samples. Parallel RNA, DNA, and protein extraction from the same experimental sample is increasingly in demand by researchers interested in gene regulation mechanisms, such as knockdown of mRNA expression by siRNAs and other processes that influence protein expression. This method is preferable to isolating RNA, DNA, and protein from different sample aliquots, which is difficult when the amount of starting material is limited and necessitates proof of sample equality to provide reliable results.

The nucleic acids are separated by sequential elution steps. First the DNA is eluted with DNA Elute, a low-ionic strength buffer, while the RNA is still bound to the column. DNA elution is followed by wash steps, on-column DNA digestion (to remove residual DNA contamination), and elution of high-quality RNA. Proteins in the flowthrough are precipitated by a special buffer (Protein Precipitator), pelleted by centrifugation, washed, and then dissolved in Protein Solving Buffer. Isolated RNA and DNA are of high quality and ready to use for all common downstream applications. Isolated protein may be used directly for quantification, SDS-PAGE, or Western blot analysis.