2.3. Peptide Preparation

S. mekongi adult worms and eggs were dissolved in 8 M urea and sonicated on ice for 10 s. The lysates were centrifuged for 20 min at 20,000 g, 4 °C. The supernatants and mouse sera were individually filtered using Amicon Ultra 0.5 mL centrifugal filters with a molecular weight cutoff of 30 kDa (Millipore, Darmstadt, Germany) by centrifugation for 20 min at 15,000× g, 4 °C. The flowthrough peptides were enriched using reverse phase C18 ZipTip chromatography (Millipore). The tips were pre-rinsed with 50% acetonitrile then equilibrated with 0.1% trifluoroacetic acid (TFA). The samples were loaded onto the zips and washed with 0.1% TFA, 80% acetonitrile. The peptides were dried using a speed vacuum (Tomy, Tokyo, Japan).