et al.[6]. Briefly, representative fragments of tumorous and non-tumorous liver tissue were immediately used to extract the total proteins, or were snap-frozen in liquid nitrogen and stored at -80°C until used for liver protein preparation. The specimens were then carefully sampled, fixed in 10% formalin, embedded in paraffin and routinely processed for diagnosis purposes. A total of 30~80 mg tissues were

grinded into powder in liquid nitrogen, dissolved Palbociclib manufacturer in 400 μl lysis buffer consisting of 7 mol/L urea, 2 mol/L thiourea, 2% NP-40, 1% Triton X-100, 100 mmol/L DTT, 5 mmol/L PMSF, 4% CHAPS, 0.5 JQ-EZ-05 mmol/L EDTA, 40 mmol/L Tris, 2% pharmalyte, 1 mg/ml DNase I, and 0.25 mg/ml RNase A, then vortexed, incubated at room temperature for 2 hr. The mixture was centrifuged (15000 r/min, 30 min, 4°C). The supernatant was the total protein solution. The concentration of the total selleck chemicals proteins was assayed with the protein assay kit (Amersham Biosciences) by comparison of the

absorbance of the diluted mixtures to a standard curve of bovine serum albumin in the range of 0–50 μg/L. 2-DE and image analysis 2-DE was performed to separate proteins as described in our previous papers [6–8]. The first dimension isoelectric focusing (IEF) electrophoresis was performed using IPG gel strip (pH 3–10 NL, 24 cm) on IPGphor (Amersham Biosciences). Briefly, 400 μg of protein samples was diluted to 450 μL with a rehydration solution [7 mol/L urea, 2 mol/L thiourea, 0.2% DTT and 0.5% (v/v) pH 3–10 IPG buffer], and applied to IPG strips (pH 3–10L, 24 cm) by 14 h ehydration

at 30 V. The proteins were focused successively for 1 h at 500 V, 1 h at 1,000 V, and 8.5 h at 8,000 V to give a total of 68 kVh on an IPGphor. Focused IPG strips were equilibrated for 15 min in a solution [6 mol/L urea, 2% SDS, 30% glycerol, Tangeritin 50 mmol/L Tris-HCl (pH 8.8), and 1% DTT], and then for an additional 15 min in the same solution except that DTT was replaced by 2.5% iodoacetamide. After equilibration, SDS-PAGE was done on Ettan DALT II system (Amersham Biosciences). After SDS-PAGE, gels were stained with silver nitrate according to the protocol of Plusone sliver staining kit (Amersham Biosciences). Each experiment was performed in triplicate. 2-DE maps were obtained by scanning the gels using the Imagescanner.