Texas Red

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Texas Red
Texas Red
Systematic name Texas Red
Chemical formula CxHxNxOx
Molecular mass 625 g/mol
Density x.xxx g/cm3
Melting point xx.x °C
Boiling point xx.x °C
CAS number [xx-xx-xx]
SMILES xxxx
Disclaimer and references
For the professional wrestler, see Mark Calaway
For the food, see chili con carne.

Texas Red (TR) is a red fluorescent dye, with a molecular weight of 625 daltons, used in histology for staining cell specimens. Texas Red is a sulfonyl chloride derivate of sulforhodamine 101. It is used for fluorescent-activated cell sorting machines, in fluorescence microscopy applications, and in immunohistochemistry. It can be excited by a dye laser tuned to 595-605 nm, or less efficiently a krypton laser at 567 nm.

Texas Red fluoresces at about 615 nm, and its absorption maximum for the excitation photons is at 589 nm. It is relatively bright, therefore can show even weakly expressed antigens.

Texas Red is a marker of proteins, with which it easily form conjugates. A protein with the chromophore attached can then act as a fluorescent labelling agent; an antibody with a fluorescent marker attached will bind to a specific antigen and then show the location of the antigens as shining spots when irradiated. Other molecules can be labeled by Texas Red as well, eg. various toxins.

Texas Red, attached to a strand of DNA or RNA, is a molecular beacon for highlighting specific sequentions of DNA. Texas Red is a derivative of sulforhodamine 101 Texas Red can be linked with another fluorophore. A tandem conjugate of Texas Red with R-phycoerythrin (PE-Texas Red) is often used.

Fluorophores, like Texas Red, are commonly used in molecular biology techniques like quantitative RT-PCR and cellular assays.