Vitros 250 chemistry analyzer

C57BL/6J mice from Jackson Laboratory (Bar Harbor, ME, USA) were maintained as described [20 (link)]. Animal experiments were conducted under the protocol (ID 1421) approved by the Institutional Animal Care and Use Committee of the University of Nebraska-Lincoln. To evaluate the effects of S-ELNs on acute liver injury induced by GalN/LPS, C57BL/6J mice were intraperitoneally injected with S-ELNs at the dose of 1 × 10¹⁰/g. The dose of S-ELNs was determined based on pilot pharmacokinetic tests and other groups’ studies [29 (link),30 (link),31 (link)]. Then, 48 h later, mice were intraperitoneally injected with a mixed solution of GalN (Sigma, 34539, 500 mg/kg) and LPS (Sigma, L2630, 15 µg/kg) to trigger acute liver damage. After 6 h, all mice were sacrificed, and serum and livers were taken for further analysis. One small piece of liver was fixed immediately in formalin solution (neutral buffered, 10%, VWR, Radnor, PA, USA), embedded in paraffin, and cut into 8-µm slices, which were placed on slides and subjected to routine Haemotoxylin and Eosin (H&E) staining or terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum were measured using a Vitros-250 Chemistry Analyzer (Johnson & Johnson, New Brunswick, NJ, USA).

Blood was collected from mice using a heparinized syringe. Concentrations of cholesterol, high‐density lipoprotein (HDL), triglyceride (TG), and blood urea nitrogen (BUN) in the plasma were determined using a VITROS 250 Chemistry Analyzer (Johnson & Johnson, Rochester, NY, USA) according to the manufacturer's instructions.

Mice were fasted for 4–6 hours and then anesthetized prior to tissue collection. Blood was collected by cardiac puncture, and the tissues and fats to be examined were dissected and collected. To obtain serum, blood samples were allowed to clot at room temperature for 15 min, and the serum was collected following centrifugation for 10 min at maximum speed in a bench top clinical centrifuge, and stored at −80 °C until use. Lipid chemistry analysis was performed using a Vitros 250 chemistry analyzer (Johnson & Johnson) by the University of Miami Comparative Pathology Laboratory Core. The levels of serum cholesterol, triglyceride, and high-density lipoprotein (HDL) were determined colorimetrically following reactions. Low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) levels were estimated as follows: VLDL = 1/5 of triglycerides; LDL = total cholesterol minus HDL and VLDL.