Tetrazolium red is used to visualize dehydrogenase enzyme activity. Initially, the tetrazolium solution is colorless but changes to red when it comes into contact with hydrogen. Tetrazolium red is used in a biochemical viability test for seeds. The test relies on dehydrogenase enzymes to release hydrogen ions, which subsequently reduce the colorless tetrazolium salt solution to a red compound called formazan. Living cells turn red while dead cells remain colorless.

Substrate for horseradish peroxidase (HRP). HRP catalyzes oxidation of 4-chloro-1-naphthol in the presence of peroxide to the blue, insoluble product 4-chloro-1-naphthon. It is used for both blotting and immunohistochemical staining, but is less sensitive than other precipitating HRP substrates.

5-Cyano-2,3-di-(p-tolyl)tetrazolium chloride is a redox dye that indicates cellular respiration activity in cells, then undergoes reduction to produce a fluorescent formazan in the presence of oxygen.

7-Methoxycoumarin, commonly referred to as Herniarin, is a methoxy derivative of coumarin and substrate for dealkylase. It has been used in the synthesis of anti-first-pass effect compounds and detergents. 7-Methoxycoumarin has been used in hepatic studies and antioxidant studies and when bound to bromomethyl at the 4 position it can be used as a fluorescent label for fatty acids.

8-Methoxypyrene-1,3,6-trisulfonic acid is used as a fluorescent marker or as a fluorescent probe for studying cationic surfactants.

Acriflavine HCl is a compound predominantly used in cellular biology for fluorescence staining. It intercalates between the base pairs of DNA and RNA. Among the acridine dyes, acriflavine has the highest affinity for DNA. Acriflavine stains eukaryotic cells exceptionally well in humic substance environments. It provides a robust experimental consistency and reduces the effect of minor experimental errors. The binding of acriflavine to DNA can be observed from a characteristic red shift in an absorption spectrum. While having a high affinity for DNA, acriflavine is limited to euchromatin for both DNA and RNA.

Acriflavine has also been found to inhibit heterodimeric transcription factors, specifically called hypoxia-inducible factors (HIFs). Studying the hyperactivity of HIFs has become a popular in oncology research, where chemicals like acriflavine are used to disrupt HIF activity of malignant cells. HIFs are activated in hypoxic conditions and promote angiogenesis to alleviate stress. They are normally regulated through proline and asparagine hydroxylation. Acriflavine halts HIF activity, specifically by binding to a subdomain of HIF-1α and HIF-2α.