Alexa fluor 647 conjugated anti rabbit secondary antibody

For in vivo Dox-L biodistribution analysis, 4T1 tumor-bearing mice were randomly distributed into two groups (n = 3) for different treatment: Dox-L (control) and Losartan + Dox-L. The 4T1 tumor-bearing mice from the group Losartan + Dox-L were injected intraperitoneally with 200µL 4 mg/mL losartan for 5 days before Dox-L injection. The 4T1 tumor-bearing mice from both groups received injection with Dox-L at a dose of 5mg/kg via the tail vein. Tumors were surgically excised at 12h post-injection to make frozen sections. Staining for blood vessels was done by incubation with rabbit anti-CD31 mouse monoclonal antibody (mAb) (dilution 1:200, Cell Signaling Technology, USA) and Alexa Fluor^®647-conjugated anti-rabbit secondary antibody (dilution 1:500, Cell Signaling Technology, USA). DAPI was applied to stain cell nuclei (dilution 1:5000, USA). The images were captured with confocal microscopy (Nikon A1 Ti, Japan).