The compound is usually a mixture of two monosulfonyl chlorides, i.e., as pictured, or with the SO3 and SO2Cl groups exchanged.

It can be used as a marker of proteins, with which it easily forms conjugates via the sulfonyl chloride (SO2Cl) group.

A protein with the Texas Red chromophore attached can then itself act as a fluorescent labeling 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.

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

[3] Newer rhodamine derivatives, such as Alexa 594 and DyLight 594, have been tailored to match the excitation and emission spectra of Texas Red and are used in various chemical and biological applications where greater photostability or higher fluorescence intensity are needed.