Sulfo Cy7 tyramide is a red fluorescent dye (Ex=740 nm, Em=770 nm) that serves as a reporter fluorescent substrate for horseradish peroxidase (HRP) catalyzed deposition, utilized in tyramide signal amplification (TSA). It is also applicable for multicolor immunohistochemistry experiments (mIHC).

Sulfo Cy7 tyramide detection involves the following steps: First, cells are fixed in 3.7% paraformaldehyde at room temperature for 20 minutes and rinsed twice with 1x PBS. Next, they are permeabilized with 0.1% Triton X-100 at room temperature for 1 to 5 minutes, followed by two washes with 1x PBS. Cells are then incubated in a 1x PBS solution containing 3% H₂O₂ for 10 minutes to block endogenous peroxidase activity, followed by two more rinses with 1x PBS. Subsequently, cells are incubated in a 1x PBS solution with 1% BSA at 4°C for 30 minutes. The primary antibody working solution is added, and incubation occurs at room temperature for 1 hour or overnight at 4°C, followed by three 5-minute washes with 1x PBS. Then, 100 µL of the secondary antibody-HRP working solution is added, incubated at room temperature for 1 hour, and washed three times with 1x PBS for 5 minutes each. Finally, 100 µL of the Sulfo Cy7 tyramide working solution is added, incubated at room temperature for 5 to 10 minutes, and washed three times with 1x PBS, each for 5 minutes. Fluorescence is then detected using a microscope. Note: It is recommended to determine the optimal concentration of the Sulfo Cy7 tyramide working solution based on specific requirements.