Masson trichrome staining kit

Four‐week‐old female BALB/c‐nu/nu mice (obtained from the Laboratory Animal Center of SUN YAT‐SEN University) were kept in the Animal Room F zone of Zhongshan School of Medicine; 1 × 10⁶ CFPAC‐1 or PANC‐1 cells with 2 × 10⁶ CAFs#1 cells in 150 μL PBS were inoculated subcutaneously into the left flank of nude mice. Tumors were measured every 3 days. Tumor volume was calculated with the formula: V = 0.5 × length × width 2. The tumor‐bearing mice were killed 33 days after inoculation, and the tumors were subsequently removed for further study. Tumor slices were stained using a Masson Trichrome Staining Kit (LEAGENE, #DC0033). Digital microphotographs (200× and 400×) were taken using a NIKON Eclipse Ci microscope, and three microscopic fields were randomly selected. The images were analyzed using ImageJ software (version 1.8), and the average stromal proportions were calculated. The detailed operating protocol using ImageJ software can be found in Section 2.5.