Resazurine

Resazurin

Names
IUPAC name 7-hydroxy-10-oxidophenoxazin-10-ium-3-one
Other names Alamar Blue, Vybrant, UptiBlue
Identifiers
CAS Number	550-82-3 Y 62758-13-8 (sodium salt) N
3D model (JSmol)	: Interactive image
ChemSpider	10606 N
ECHA InfoCard	100.008.171
PubChem CID	11077
InChI InChI=1S/C12H7NO4/c14-7-1-3-9-11(5-7)17-12-6-8(15)2-4-10(12)13(9)16/h1-6,14H N Key: PLXBWHJQWKZRKG-UHFFFAOYSA-N N InChI=1/C12H7NO4/c14-7-1-3-9-11(5-7)17-12-6-8(15)2-4-10(12)13(9)16/h1-6,14H Key: PLXBWHJQWKZRKG-UHFFFAOYAB
SMILES : C1=CC2=C(C=C1O)OC3=CC(=O)C=CC3=[N+]2[O-]
Properties
Chemical formula	C12H7NO4
Molar mass	229.19 g·mol−1
Solubility in water	soluble
Hazards
GHS pictograms
GHS signal word	Warning
GHS hazard statements	H315, H319, H335
GHS precautionary statements	P261, P305+351+338
NFPA 704	1 2 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Resazurin (7-Hydroxy-3H-phenoxazin-3-one 10-oxide) is a blue dye, itself weakly fluorescent until it is irreversibly reduced to the pink colored and highly red fluorescent resorufin. It is used as an oxidation-reduction indicator in cell viability assays for both aerobic and anaerobic respiration. Usually it is available commercially as the sodium salt.

Resazurin solution has one of the highest values known of Kreft's dichromaticity index. This means that it has a large change in perceived color hue when the thickness or concentration of observed sample increases or decreases.

Resazurin was first used to quantify bacterial content in milk by Pesch and Simmert in 1929. It is also used as an indicator for cell viability in mammalian cell cultures. It was introduced commercially initially under Alamar Blue trademark (Trek Diagnostic Systems, Inc), and now also available under other names such as AB assay, Vybrant (Molecular Probes) and UptiBlue (Interchim).

Resazurin based assays show excellent correlation to reference viability assays such as formazan-based assays (MTT/XTT) and tritiated thymidine based techniques, while being much easier and safer to use for the user. It also allows for longer studies (minimally toxic to living cells), works for adherents cells and bacteria/fungi. Besides standard applications as cell culture assays (cell counting, cell proliferation assays) and cytotoxicity testing, it also can be multiplexed with several chemiluminescent assays, such as cytokine assays, caspase assays to measure apoptosis, or reporter assays to measure a gene or a protein expression. The irreversible reaction of resazurin to resorufin is proportional to aerobic respiration.

Resazurin is effectively reduced in , making it useful also to assess metabolic activity.

Usually, in the presence of NADPH dehydrogenase or NADH dehydrogenase as the enzyme, NADPH or NADH is the reductant that converts resazurin to resorufin. Hence the resazurin/diaphorase/NADPH system can be used to detect NADH, NADPH, or diaphorase level, and any biochemical or enzyme activity that is involved in a biochemical reaction generating NADH or NADPH.