Fixation and TMA preparation according to PMID: 22688270.
Cut 4µm TMA sections using a waterfall microtome (ThermoFisher Scientific, HM355S).
Dry sections ON at RT and then back them for 12-24h at 50°C.
Deparaffinization and rehydration in xylene and graded alcohol series:
xylene twice for 3min.
100% ethanol for 1min.
95% ethanol for 1min.
0.3% H2O2 in 95% ethanol for 5min to block endogenous peroxidase.
70% ethanol for 1min.
50% ethanol for 1min.
distilled H2O for 2min.
Antigen Retrieval by Heat Induced Epitope Retrieval (HIER):
Boil the sections in Lab Vision Citrate buffer pH6.0 (ThermoFisher Scientific, TA-250-PM1X) for 4min at 125°C in a decloaking chamber (Biocare Medical).
Allow slides to cool down to 90°C in the decloaking chamber.
Immunostaining in a Lab Vision Autostainer 480 (ThermorFisher Scientific) at RT with 300µl of reagents for each step:
Rinse sections in Lab Vision wash buffer with extra tween added to a final concentration of 0.2% (ThermoFisher Scientific, TA-999-TT and TA-125-TW) wash buffer.
Block sections with Lab Vision Ultra V-Block (ThermoFisher Scientific, TA-125-UB) for 5min.
Rinse sections 2x in wash buffer.
Incubate sections with primary rabbit anti-MADCAM1 antibody (antibodies-online, ABIN3044076) diluted 1:900 for 30min.
Rinse sections 3x in wash buffer.
Incubate sections with labeled HRP polymer (ThermoFisher Scientific, TL-125-PH) for 30min.
Rinse sections 2x in wash buffer.
Develop in DAB Quanto solution (ThermoFisher Scientific, TL-125-QHDX) for 5min.
Rinse sections in distilled H2O.
Washing, counterstaining, and coverslipping in Autostainer XL (Leica Biosystems, ST5010) at RT:
Counterstaining in Mayer’s hematoxylin plus (HistoLab, 01820) for 7.5min.
Rinse sections in tap water for 5min.
Rinse sections in lithium carbonate water diluted 1:5 for 5min.
Dehydration in graded ethanol series and Neo-Clear (Merck Millipore, 109843) according to the manufacturer recommendations.
Automated mounting (Leica Biosystems, CV5030) of coverslip with Pertex (Histolab, 00871).
Microscopy:
Image acquisition on a Leica Aperio AT2 and Aperio Scanscope AT at 20x magnification.
Anmerkungen
ABIN3044076 shows nice staining in a subset of vessels (endothelial cells), present in intestine and spleen.