Mx35 premier blades

At the time of collection, mice tissue samples (perfused lungs, dorsal skin, inguinal lymph nodes or tumors) were collected and fixed overnight in PFA 4% at 4 °C. Samples were then washed three times in PBS, processed in an STP 120 Spin Tissue Processor (ThermoFisher Scientific, MA, USA; cat# 813150) overnight and embedded in paraffin (Hounisen, DK; cat# 2270.6060) using a Microm EC 350 modular tissue embedding center (ThermoFisher Scientific, MA, USA). Unless otherwise indicated, sections of 4 µm were cut using an HM325 rotary microtome (ThermoFisher Scientific, MA, USA; cat# 902100), MX35 Premier blades (ThermoFisher Scientific, MA, USA; cat# 3051835) and ThermoScientific™ SuperFrost Plus™ Adhesion slides (ThermoFisher Scientific, MA, USA; cat# J1800AMNZ). Sections were deparaffinized with xylene and graded ethanol, and rehydrated. Sections were then stained according to various staining procedures.

Midges for IHC analyses were embedded in paraffin wax as described previously [35 (link)], and stored at room temperature. Embedded midges were serially cut in 5 μm sagittal sections using a Leica RM2235 microtome (Leica, Wetzlar, Germany) with MX35 Premier blades (Thermo Fisher Scientific). Sections were mounted onto positively charged microscope slides (Premiere, C&A Scientific, Manassas, VA, USA) and kept on a slide warmer at 40°C overnight. Midges fed a non-infectious blood meal and IT-infected midges were used as negative and positive controls, respectively, and processed in parallel to the experimental samples.