Cm1850 uv

Huangqi samples were sectioned using a freezing microtome (Leica CM1850 UV, 30–40 μm) at 20–40-μm thickness, and the sections were stained with 5% sodium hydroxide solution. After few minutes, the sections were observed using fluorescence microscopy (Leica DM6000B; Leica Microsystems, Fluo, Germany) with a green filter (Leica Microsystems, Germany) and an emission wavelength of 420 nm. Huangqi samples were also sectioned using a freezing microtome (Leica CM1850 UV, 30–40 μm) at 20–40-μm thickness, and the sections were stained with 5% vanillin-sulfuric acid solution. After few minutes, saponins may become red or purple. Sections for a negative control experiment were treated with 70% alcohol for 1 month to remove flavonoids and saponins. These sections were then stained with 5% sodium hydroxide solution or 5% vanillin-sulfuric acid solution, as described previously.

LNCaP xenograft tumour was used for the MSI studies. Tissues were cut in a way that mimics a sagittal plane of slicing, as there is no spatial orientation with xenograft tumour. Cryosectioning was performed using a Leica cryotome (CM 1850 UV, Wetzlar, GmbH & Co. KG) at −18 °C and 12 μm tissue thickness. Sections were thaw-mounted onto conductive indium-tin-oxide (ITO)-coated slides (Bruker Daltonik, Bremen, GmbH & Co. KG), dried in a vacuum desiccator at room temperature for 30 min, and then stored at −80 °C until MSI analysis.