306-N16B

Reverse transcription technology uses RNA as a template to synthesize DNA. RT-PCR is simple, specific and sensitive, and can be used to detect gene expression levels and expression differences in cells; detect RNA virus content; clone cDNA sequences of specific genes.

Gene editing modify specific sites within the genome through gene deletions, insertions or conversions to study functionally unknown genes or conduct gene therapy. It is also used to change the biological traits of organisms to establish new varieties. Gene editing techniques include zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas 9) (CRISPR/Cas9).

By lysing cells, releasing RNA, and removing impurities such as proteins and DNA, high-purity RNA products are finally obtained. The commonly used traditional method is the guanidine isothiocyanate/phenol/chloroform method (Trizol), which is suitable for a variety of animal materials including animal tissues, microorganisms, cultured cells, etc., and most plant materials.

Endothelial tube formation assay evaluates the ability of endothelial cells to attach, migrate, align, and organize into capillary-like networks when cultured on gelled basement membrane extract or Matrigel; the readout is the morphology and quantity of tube-like networks, which reflects an in vitro endothelial morphogenesis step related to angiogenesis. Basement membrane extract/Matrigel provides laminin-rich extracellular matrix cues that support endothelial differentiation into capillary-like structures, but it can contain biologically active growth factors, so growth-factor-reduced matrix is preferred when testing defined angiogenic stimulators or inhibitors.

Real-time quantitative PCR (qPCR) quantifies an amplifiable nucleic-acid target by monitoring fluorescence during PCR cycling rather than measuring product only after amplification. The increase in fluorescence tracks accumulation of PCR product, and the quantification cycle (Cq; historically also Ct/CP) is related to the initial amount of target: samples containing more starting target generally reach the defined fluorescence threshold in fewer cycles.

CRISPR-Cas9 editing of human pluripotent stem cells uses a guide RNA to direct Cas9 to a genomic target, where Cas9 creates a double-strand break that is repaired mainly by non-homologous end joining for knockout mutations or by homology-directed repair when a donor template is supplied for precise knock-in or sequence correction. The readout is generated by genotyping edited bulk populations or single-cell-derived clones, using PCR, sequencing, restriction-based assays, reporter fluorescence, or allele-specific analysis to distinguish unedited alleles, indels, precise donor-mediated edits, biallelic deletions, and unwanted on-target lesions.