RNAextrakt

RNA extract, or RNAextrakt, refers to RNA-containing material isolated from biological samples for molecular analyses such as gene expression studies and sequencing. An RNA extract may be total RNA or enriched for certain RNA types (e.g., mRNA) depending on the purification approach. The extract's quality and integrity are critical for downstream results.

Extraction methods used to obtain RNA extracts include organic extraction with phenol-chloroform, guanidinium-based lysis with silica-based purification, and magnetic bead–based methods. The general aim is to lyse cells or tissues, inactivate RNases, and separate RNA from DNA and proteins. Care is taken to prevent RNA degradation by using RNase-free reagents and maintaining low temperatures.

Quality assessment of RNA extracts typically involves measuring concentration and purity spectrophotometrically, with A260/A280 around 2.0 indicating pure RNA and A260/A230 providing an additional purity check. RNA integrity is assessed by electrophoretic methods or using an RNA integrity number (RIN). Residual DNA may be removed by DNase treatment if required for the intended downstream applications.

Storage and handling considerations include storing RNA extracts at -70 to -80 C for long-term preservation and at 2-8 C for short-term use, with aliquoting to avoid repeated freeze-thaw cycles. Because RNases are pervasive, work is conducted in RNase-free environments using dedicated equipment and proper personal protective equipment.

Applications of RNA extracts span quantitative and qualitative analyses such as RT-qPCR, RNA sequencing, Northern blotting, and expression profiling in research and clinical diagnostics. It is important to distinguish between total RNA extracts and RNA enriched for specific subsets (e.g., mRNA) via poly-A selection or rRNA depletion.