Indium tin oxide glass slides

The isoflurane anaesthetic and nitrogen 4.0 were obtained from Baxter and Linde (both Bratislava, Slovak Republic), respectively. The indium-tin oxide (ITO) glass slides and α-cyano-4-hydroxycinnamic acid (CHCA) were obtained from Bruker Daltonics (Bremen, Germany). Acetonitrile, methanol, ethanol and water (all LC-MS grade) were obtained from Merck Millipore (Prague, Czech Republic). Trifluoroacetic acid (TFA), chloroform, sodium chloride, 9-aminoacridine (9-AA), haematoxylin solution, Gill no. 2 and DPX mounting media were obtained from Sigma-Aldrich (Prague, Czech Republic). Eosin Y (0.5%) aqueous solution was purchased from VWR Chemicals (Stribrna Skalice, Czech Republic). Hydrochloric and nitric acid (65%, Analpure) were obtained from FlukaBioChemika or Analytika Ltd., respectively (both Prague, Czech Republic). Deionized water (18.2 MΩ/cm) was prepared using a Milli-Q system (Millipore, Molsheim, France). Omni Slides with hydrophobic surfaces were purchased from Prosolia, Inc. (Zionsville, USA).

Xylene (analytical grade), ammonium bicarbonate, Sodium citrate, trifluor-acetic acid (TFA), formic acid (FA), acetic acid (AcOH), acetonitrile (ACN), methanol and α-Cyano-4-hydroxycinnamic acid (CHCA) were purchased from Sigma. Polyimide coated fused silica capillary (75 μm ID) was from PostNova, C₁₈ Reprosil Pur reversed phase material was from Dr. Maisch (Ammerbuch-Entringe, Germany), recombinant Trypsin was purchased from Promega (WI, USA), Indium-tin-oxide (ITO) glass slides were purchased from Bruker (Bremen, Germany), water was Milli-Q filtered.

All chemicals were commercially available and of the highest purity. Pimonidazole (Hypoxyprobe-1) was purchased from HPI Inc. (Burlington, MA, USA). HPLC-grade methanol and acetonitrile were purchased from Kanto Chemical Co., Inc. (Tokyo, Japan). Trifluoroacetic acid (TFA), ammonium hydrogen carbonate and the reduced form of glutathione were from Wako Pure Chemical Co., Ltd. (Osaka, Japan). The oxidized form of glutathione was from Nacalai Tesque, Inc. (Kyoto, Japan). 2,5-Dihydroxybenzioc acid (DHB) and indium tin oxide (ITO) glass slides were purchased from Bruker Daltonics (Billerica, MA, USA). Complete protease inhibitor cocktail was from Roche Diagnostics (Basel, Switzerland).