Light Green SF yellowish

Light Green SF yellowish

Names
IUPAC name ethyl-[4-[[4-[ethyl-[(3-sulfophenyl)methyl]amino]phenyl]-(4-sulfophenyl)methylene]-1-cyclohexa-2,5-dienylidene]-[(3-sulfophenyl)methyl]ammonium
Identifiers
CAS Registry Number	Y
ChemSpider	Y
InChI InChI=1S/C37H36N2O9S3.2Na/c1-3-38(25-27-7-5-9-35(23-27)50(43,44)45)32-17-11-29(12-18-32)37(31-15-21-34(22-16-31)49(40,41)42)30-13-19-33(20-14-30)39(4-2)26-28-8-6-10-36(24-28)51(46,47)48;;/h5-24H,3-4,25-26H2,1-2H3,(H2-,40,41,42,43,44,45,46,47,48);;/q;2*+1/p-2 Y Key: DGOBMKYRQHEFGQ-UHFFFAOYSA-L Y InChI=1/C37H36N2O9S3.2Na/c1-3-38(25-27-7-5-9-35(23-27)50(43,44)45)32-17-11-29(12-18-32)37(31-15-21-34(22-16-31)49(40,41)42)30-13-19-33(20-14-30)39(4-2)26-28-8-6-10-36(24-28)51(46,47)48;;/h5-24H,3-4,25-26H2,1-2H3,(H2-,40,41,42,43,44,45,46,47,48);;/q;2*+1/p-2 Key: DGOBMKYRQHEFGQ-NUQVWONBAW
Jmol-3D images	Image
KEGG	N
PubChem
SMILES [Na+].[Na+].[O-]S(=O)(=O)c1cccc(c1)CN(c2ccc(cc2)\C(=C\4/C=C\C(=[N+](\CC)Cc3cccc(c3)S([O-])(=O)=O)/C=C/4)c5ccc(cc5)S([O-])(=O)=O)CC
Properties
Chemical formula	C37H37N2O9S3+
Molar mass	749.893 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (: Y/N?)

Light Green SF yellowish, or Light Green, Acid Green, Lissamine green SF, Acid Green 5, Food Green 2, FD&C Green no. 2, Green No. 205, Acid Brilliant Green 5, Pencil Green SF, or C.I. 42095, is a green triarylmethane dye. It is used in histology for staining collagen; for that purpose it is a standard dye in North America. In Masson's trichrome it is used as a counterstain to acid fuchsin. It is a critical component of Papanicolaou stains together with eosin Y and bismarck brown Y. It usually comes as a disodium salt. Its maximum absorption is at 630 (422) nm.

The dye is not very durable — it has a tendency to fade. When fading is to be avoided, it is replaced with Fast Green FCF, which also has more brilliant color. Fast Green FCF can also substitute Light Green SF yellowish in many other procedures.

Lissamine green dye can be used to check the health of the anterior surfaces of the eye. It is available on a steret. The steret is wet with saline and then the dye is dropped into the lower fornix. The dye shows up conjunctival staining similar to rose Bengal dye but it does not sting like rose Bengal does.