| abstract |
The invention provides an asymmetric cyanine fluorescent dye expressed in the formula I (please see the formula in the specification). X, n, R1, R2, R3, R4 and Y are defined in the specification. The dye can be used as an excellent nucleic acid dyeing agent, the spectrum of the dye is in a near infrared region of 600 nm to 900 nm, and interference of background fluorescence does not exist. Meanwhile, according to the dye, a small red semiconductor laser can be used as a light source (633 nm). The invention further provides a composition containing the fluorescent dye and a method for using the fluorescent dye or the composition of the fluorescent dye in biological dyeing. |