Ethynylferrocene

The EdU incorporation assay measures DNA synthesis by adding the thymidine analog 5-ethynyl-2′-deoxyuridine to cells or tissues, where it is incorporated into newly synthesized DNA during S phase. Incorporated EdU is detected by copper-catalyzed azide-alkyne cycloaddition, in which a fluorescent azide covalently reacts with the ethynyl group on EdU, allowing S-phase cells to be detected by fluorescence microscopy, flow cytometry, or high-content imaging. EdU detection does not require DNA denaturation or anti-BrdU antibody access, which preserves sample structure and improves compatibility with immunostaining and multiparameter cytometry compared with BrdU-based detection. EdU can be cytotoxic in a cell-type- and exposure-dependent manner, so pulse duration, concentration, and continuous-labeling designs should be validated for each cell type.

Southern blot is a DNA hybridization assay used to detect a defined DNA sequence within restriction-digested or otherwise fragmented genomic DNA. The method separates DNA fragments by agarose gel electrophoresis, transfers the size-resolved DNA pattern onto a solid support, denatures the DNA to permit base pairing, and detects fragments that hybridize with a complementary labeled probe; the readout is a band, smear, or fragment-size distribution corresponding to the target sequence and its restriction-fragment context. The assay reflects sequence presence, restriction fragment length, gene copy pattern, structural rearrangement, insertion or deletion affecting restriction sites, and some repeat-length or terminal restriction fragment applications when the experimental design links the probe to those genomic features. Classic applications include Southern blot-based telomere terminal restriction fragment analysis and minisatellite-based DNA fingerprinting, which illustrate how the same