T7 RNA Polymerase

This assay tests the enzyme's ability to transcribe RNA from a DNA template under controlled in vitro conditions. By mimicking a standard RNA transcription reaction, this test assesses both the activity and efficiency of the T7 RNA Polymerase. The reaction includes a DNA template containing a T7 promoter, ribonucleotides (NTPs), and reaction buffer components like magnesium. After incubation, RNA output is quantified using spectrophotometric measurements or gel electrophoresis to evaluate yield and size. Activity is assessed based on RNA production levels and transcript integrity. Successful results indicate the enzyme can reliably perform its primary function, producing high-quality RNA suitable for downstream applications, such as RNA probe synthesis, mRNA production, and CRISPR guide RNA transcription.

Manufactured via recombinant expression in Escherichia coli, T7 RNA Polymerase is tested for residual genomic DNA from the host organism. This assay uses sensitive detection methods like quantitative PCR (qPCR) or digital PCR using primers specific to E. coli genomic sequences to confirm the absence of E. coli DNA contamination, which could otherwise introduce unintended sequences into RNA transcripts. These techniques can detect even trace amounts of host DNA. A negative result confirms that the T7 RNA Polymerase preparation is free from E. coli contaminants and suitable for sensitive research and therapeutic applications.

This assay determines whether RNase, an enzyme that degrades RNA, is present in the preparation. RNase contamination can significantly compromise RNA integrity, leading to degraded or incomplete RNA transcripts. The test involves incubating a known RNA sample with the T7 RNA Polymerase preparation under physiological conditions. RNA degradation is evaluated using gel electrophoresis or fluorescence-labeled RNA decay assays. A negative result confirms the enzyme is RNase-free, safeguarding the integrity of RNA products for downstream applications like RNA structural analysis and gene therapy workflows.

The protein purity test evaluates the proportion of T7 RNA Polymerase present in the final preparation, ensuring it constitutes at least 90% of the total protein content. High protein purity reduces the likelihood of contaminants interfering with the enzyme's performance. Protein purity is evaluated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) or high-performance liquid chromatography (HPLC). These methods quantitatively determine the proportion of T7 RNA Polymerase relative to total protein content in the preparation. A purity of ≥ 90% ensures minimal contamination, reliable enzyme activity, and compatibility with demanding applications such as mRNA synthesis and CRISPR guide RNA production.