R-Phycoerythrin (ammonium sulfate precipitate)

R-Phycoerythrin (R-PE) (ammonium sulfate precipitate) is found in Heterosiphonia japonica. R-Phycoerythrin (ammonium sulfate precipitate) is an orange-red fluorescent probe with α, β, and γ subunits. R-Phycoerythrin (concentrated solution) can be used in photodynamic therapy (PDT) to induce apoptosis in tumor cells. R-Phycoerythrin (ammonium sulfate precipitate) can be used in fluorescence microscopy, flow cytometry, and immunofluorescence analysis (Ex/Em = 496/578 nm)^[1][2]. In Vitro:R-Phycoerythrin ammonium sulfate precipitate needs to be desalted and the solution changed to phosphate buffer before use.
R-Phycoerythrin (10-100 μM, 4 h) is cytotoxic to S180 in a concentration-dependent manner (58%)^[2].

Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
Specific steps^[2]:
1. Cell treatment and staining
1.1 S180 and SMC7721 cancer cells were cultured in RPMI1640 medium containing 10% fetal bovine serum and 1% penicillin/streptomycin to the logarithmic growth phase (37°C, 5% CO₂, 95% air humidity).
1.2 The cells were seeded at a density of approximately 5 × 10⁵/mL in serum-free RPMI1640 medium and incubated with different concentrations of R-Phycoerythrin (10, 25, 50, 100 μM) for 4 hours.
2. Light treatment
2.1 Use 496 nm argon laser to excite R-Phycoerythrin, β subunit, γ subunit, and 514 nm to excite α subunit.
2.2 Change to RPMI1640 medium containing 10% serum and continue incubation for 18 hours.
2.3 Use MTT method to detect the survival rate of S180 cells.