Calcein: Difference between revisions

| verifiedrevid = 443494137

| Name = Calcein

| ImageFile = Calcein.svg

| ImageName =

| IUPACName =

| Section1 = {{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| InChI = 1/C30H26N2O13/c33-21-7-23-19(5-15(21)9-31(11-25(35)36)12-26(37)38)30(18-4-2-1-3-17(18)29(43)45-30)20-6-16(22(34)8-24(20)44-23)10-32(13-27(39)40)14-28(41)42/h1-8,33-34H,9-14H2,(H,35,36)(H,37,38)(H,39,40)(H,41,42)

| InChIKey = DEGAKNSWVGKMLS-UHFFFAOYAD

| ChEBI_Ref = {{ebicite|correct|EBI}}

| SMILES = O=C(O5)c1ccccc1C (c3cc(CN(CC(O)=O) CC(O)=O)c(O)cc3O4) 5c2c4cc(O)c(CN(CC (O)=O)CC(O)=O)c2

| Section2 = {{Chembox Properties

| Formula = C₃₀H₂₆N₂O₁₃

| MolarMass = 622.55 g/mol

| Density =

| MeltingPt = Decomposes

| BoilingPt = N/A

'''Calcein''', also known as '''fluorexon, [[fluorescein]] complex''', is a [[fluorescent]] [[dye]] with an [[Excited state|excitation]] and [[Emission (electromagnetic radiation)|emission]] wavelengths of 495/515&nbsp;nm, respectively. Calcein also self-[[quenching (fluorescence)|quenches]] even at concentrations below 100mM<ref>Patel et al. Characterizing vesicle leakage by fluorescence lifetime measurements (doi: 10.1039/b908524f)</ref>. It is used as a [[complexometric indicator]] for [[titration]] of [[calcium]] ions with [[EDTA]], and for [[fluorometric]] determination of calcium. It has the appearance of orange crystals.

The acetomethoxy derivate of calcein ('''calcein AM''') is used in biology as it can be transported through the cellular membrane into live cells, which makes it useful for testing of cell [[viability]] and for short-term labeling of cells. An acetomethoxy group obscures the part of the molecule that chelates Ca²⁺, Mg²⁺, Zn²⁺ and other ions. After transport into the cells, intracellular esterases remove the acetomethoxy group, the molecule gets trapped inside and gives out strong green fluorescence. As dead cells lack active esterases, only live cells are labeled<ref>{{cite web |url=http://www.howstuffworks.com/light-microscope4.htm |title=How Light Microscopes Work |publisher=HowStuffWorks }}</ref> and counted by [[flow cytometry]].

Calcein is now rarely used as a Ca²⁺ or Mg²⁺ indicator because its fluorescence is directly sensitive to these ions only at strongly alkaline pH, and thus it is not particularly useful for measuring Ca²⁺ or Mg²⁺ in cells. Fluorescence of calcein is quenched strongly by Co²⁺, Ni²⁺ and Cu²⁺ and appreciably by Fe³⁺ and Mn²⁺ at physiological pH. This fluorescence quenching response can be exploited for detecting the opening of the mitochondrial permeability transition pore. Calcein is commonly used for cell tracing and in studies of endocytosis and gap junctions.<ref>{{cite book |author= |chapter=Fluorescent Indicators for Zn²⁺ and Other Metal Ions—Section 19.7 |chapterurl=http://www.invitrogen.com/site/us/en/home/References/Molecular-Probes-The-Handbook/Indicators-for-Ca2-Mg2-Zn2-and-Other-Metal-Ions/Fluorescent-Indicators-for-Zn2-and-Other-Metal-Ions.html |title=Molecular Probes: The Handbook |publisher=invitrogen |url=http://www.invitrogen.com/site/us/en/home/References/Molecular-Probes-The-Handbook.html }}</ref>

The acetoxymethyl ester of calcein is also used to detect drug interactions with '''multidrug resistance proteins''' (ABC transporters [[ATP-binding cassette transporter genes]]) in intact cells as it is an excellent substrate of the multidrug resistance transporter 1 (MDR1) [[P-glycoprotein]] and the [[:de:Multidrug Resistance-Related Protein]] (MRP1).<ref>{{cite journal |author=Glavinas H, Krajcsi P, Cserepes J, Sarkadi B |title=The role of ABC transporters in drug resistance, metabolism and toxicity |journal=Curr Drug Deliv |volume=1 |issue=1 |pages=27–42 |year=2004 |month=January |pmid=16305368 |doi= 10.2174/1567201043480036|url=http://www.bentham-direct.org/pages/content.php?CDD/2004/00000001/00000001/005AU.SGM}}</ref> The calcein AM assay can be used as a model for drug-drug interactions, for screening transporter substrates and/or inhibitors;<ref>more detailed description of the assay/ http://www.solvo.com/pdfs/SOLVO%20Calcein%20Assay.pdf</ref> and also to determine in vitro drug resistance of cells, including samples from patients.<ref>a detailed description of the method http://www.solvo.com/pdfs/MDQ%20flyer.pdf</ref><ref>{{cite journal |doi=10.1046/j.1365-2141.2001.02554.x |author=Karászi E, Jakab K, Homolya L, ''et al.'' |title=Calcein assay for multidrug resistance reliably predicts therapy response and survival rate in acute myeloid leukaemia |journal=Br. J. Haematol. |volume=112 |issue=2 |pages=308–14 |year=2001 |month=February |pmid=11167823 |url=http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0007-1048&date=2001&volume=112&issue=2&spage=308}}</ref>

Calcein is also used for marking freshly hatched [[fish]]<ref>{{cite web |url=http://www.gct.org.uk/text03.asp?PageId=331 |title=Marking fry using calcein |publisher=Game & Wildlife Conservation Trust}}</ref> and for labeling of [[bone]]s in live animals.

[[Category:Synthetic phenolic dyes]]

[[Category:Fluorescent dyes]]

[[de:Calcein]]

[[pl:Kalceina]]

[[pt:Calceína]]

[[ru:Флуорексон]]