Potassium ferricyanide

Trichloroacetic acid (TCA), gallic acid, De Man, Rogosa and Sharpe (MRS) broth, Dulbecco's modified Eagle's medium (DMEM), fetal bovine serum (FBS), and Folin–Ciocalteu's reagent were procured from Sigma‐Aldrich, Inc. Dinitrophenyl hydrazine (DNPH) was from ACROS Organics; hydrogen peroxide, methanol, and FeCl₃ were purchased from BDH Chemicals Ltd.; and thiourea, CuSO₄.5H₂O, H₂SO₄, sodium carbonate, AlCl₃, potassium acetate, Tris–HCl buffer, FeSO₄, potassium ferricyanide, and ferric chloride were of analytical grade while the water was glass‐distilled. Lipopolysaccharide (LPS), sodium nitrite (NaNO₂), and Griess reagent (0.1% N‐(1‐naphthyl)ethylenediamine dihydrochloride, 1% sulfanilamide in 5% phosphoric acid) were all prepared in‐house from reagents purchased from Sigma‐Aldrich Korea. Viscozyme, cellulase, amylase, and protease were supplied by Erom Company Limited.

α‐glucosidase from rats’ intestine, porcine pancreatic α‐amylase, pepsin, p‐nitrophenyl‐α‐D‐glucopyranoside and starch were sourced from (Sigma Chemical Co. St. Louis, MO, USA). 1,10‐phenanthroline, 1,1‐diphenyl–2 picrylhydrazyl (DPPH), Folin–Ciocalteu reagent, deoxyribose, thiobarbituric acid, Tris,3,5‐dinitrosalicylic acid, quercetin, rutin, kaempferol, catechin, epicatechin, gallic, caffeic, and chlorogenic acids were bought from Sigma‐Aldrich, Inc., St Louis, MO. Other chemicals such as aluminum chloride, potassium ferricyanide, sulfuric acid, methanol, hydrogen peroxide, ethanol, Iron (II) sulfate, potassium acetate, sodium dodecyl sulfate (SDS), sodium hydroxide, sodium chloride, potassium chloride, ferric chloride sodium carbonate, sodium acetate, phenol solution, hydrochloric, perchloric, and acetic acids were sourced from (BDH Chemicals Ltd., Poole, UK).

Chemicals and reagents used such as thiobarbituric acid (TBA), 1,10-phenanthroline, deoxyribose, gallic acid, and Folin-Ciocalteau's reagent were procured from Sigma-Aldrich, Inc. (St Louis, MO), trichloroacetic acid (TCA) was sourced from Sigma-Aldrich, Chemie GmbH (Steinheim, Germany), dinitrophenylhydrazine (DNPH) was sourced from ACROS Organics (New Jersey, USA), and hydrogen peroxide, methanol, acetic acid, thiourea, CuSO₄·5H₂O, H₂SO₄, HCl, sodium carbonate, AlCl₃, potassium acetate, Tris-HCl buffer, sodium dodecyl sulphate, FeSO₄, potassium ferricyanide, and ferric chloride were sourced from BDH Chemicals Ltd. (Poole, England), while the water was glass distilled.

Silica gel 60–120, Silica gel GF₂₅₄, catechin, tricholoroacetic acid (TCA), donezepil, galantamine, and Tris-HCl were procured from Merck, Mumbai, India. Vincristine sulfate, dimethyl sulphoxide (DMSO), potassium ferricyanide, ferric chloride, and Folin-Ciocalteau reagent were from BDH chemicals Ltd., Poole, England. Acetylthiocholine and S-butyrylthiocholine and DTNB were purchased from Sigma-Aldrich, Darmstadt, Germany. Nutrient agar media was from Becton, Dickinson, and Company (Sparks, MD, USA). Petroleum ether and methanol were purchased from Duksan Pure Chemicals Company Limited (Ansan-si, Republic of Korea). The Institute of Nutrition and Food Science, University of Dhaka donated the cultures of bacteria and fungi. The other chemicals were of analytical grade.

The determination of formalin residue was done using the phenyl hydrazine method according to the Egyptian Veterinary Codex 2009, (CLEVB). Briefly, 1 ml of standard formaldehyde solutions were freshly prepared by adding aqueous formaldehyde solution (40%) to distilled water in five test tubes representing five concentrations (1.0, 0.50, 0.1, 0.05, and 0.01%) of the formaldehyde standards. In another test tube represented the sample (1 ml of the tested inactivated vaccine added to 99 ml distilled water to achieve 1% concentration), the following reagents were put in order: 0.1 ml of phenyl hydrazine 1% (Riedel-de Haen Allied Signal, Germany), 0.1 ml of potassium ferricyanide 5% (BDH Chemicals Ltd., Poole, England) and three drops (90 µl) of concentrated hydrochloric acid (HCl) (The Egyptian Company for Chemicals and Drugs (ADWIA), Egypt). This mixture was thoroughly shaken and placed on the bench for 5 min before the color of the sample tube and the standard tubes were matched.