| Description | If the serum will not be used up within a short period of time, dispense after thawing and store aliquot under appropriate conditions for long-term storage. The volume of serum will increase by 10% after freezing, so when dispensing serum into tubes, leave some space in the tube to avoid tube If the serum will not be used up within a short period of time, dispense after thawing and store aliquot under appropriate conditions for long-term storage. The volume of serum will increase by 10% after freezing, so when dispensing serum into tubes, leave some space in the tube to avoid tube cracking during the freezing.After the serum is thawed completely, the serum can be heated at 56℃ for 30 minutes to inactivate the complement in serum. Unless necessary, heat-inactivation of the serum is not recommended for general use because heat treatment will result in precipitation of serum and decreasing of serum quality. Complement is involved in reactions such as cytotoxicity, contraction of smooth muscle cells, release of histamine from mast cells and platelets, enhancement of phagocytosis, and promotion of chemical chemotaxis and activation of lymphocytes and macrophages.The serum should be thawed slowly and gradually. Thaw the serum stored at -15~-40℃ in 4℃ refrigerator for approximately one day, and make aliquot after it is thawed thoroughly. During the thawing process, shake gently every 2 hours (avoid the formation of air bubbles) to homogenize the component and reduce the occurrence of precipitation. Do not thaw the serum stored at -20℃ or lower temperatures directly in a 37℃ water bath to avoid protein agglomeration and precipitation in serum due to large temperature changes.The floc-like precipitates in serum are mainly denatured fibrin and lipoproteins in serum after long-term storage at 4℃. These flocs do not affect the quality of the serum and can be left untreated. If necessary, the flocs can be removed by centrifugation at 400×g for 5 minutes. However, it is not advisable to remove by filtration as the flocs may block the filter membrane. The precipitates in the serum after heat inactivation will increase significantly. Some of these deposits look like "black dots" under the microscope and are often misinterpreted as microbial contamination because the Brownian motion of these "dots" is magnified under the microscope and appear to be swimming. Usually, these small black spots do not affect cell growth, but if microbial contamination of the serum is suspected, it should be immediately replaced with new serum. Users can dilute the serum with culture medium to 10% concentration and incubate for 1-3 days, and observe whether the small black dots increase sharply, or spread an appropriate amount of serum on LB plate to determine whether there is microbial contamination. Do not leave the serum at 37℃ for too long, as the serum will gradually become cloudy and lose some active ingredients, thus affecting the quality of the serum.This product is for R&D only. Not for drug, household, or other uses.For your safety and health, please wear a lab coat and disposable gloves during the operation... Read More | Biochemical Test:SDS-PAGE (purity > 80%); Western blot with patient sample.Calculated Isoelectric Point:pH 8.38 | Malic Dehydrogenase is a ubiquitous enzyme, which exists in two isoforms in eukaryotic cells.Malic dehydrogenase exists as a dimer with each subunit containing an NAD-binding domain and a substrate-binding carboxy-terminal domain required for activity. Malic dehydrogenase is a cytoplasmic isozyme Malic Dehydrogenase is a ubiquitous enzyme, which exists in two isoforms in eukaryotic cells.Malic dehydrogenase exists as a dimer with each subunit containing an NAD-binding domain and a substrate-binding carboxy-terminal domain required for activity. Malic dehydrogenase is a cytoplasmic isozyme and an important catalyst in the tricarboxylic acid cycle.ReagentsA. 0.1 M Tris-HCl buffer (pH7.8)B. 0.01 M Phosphate buffer (KH2PO4-NaOH, pH 7.0)C. Triton X-100 solution (50 mg/ml)D. 0.01 M Phosphate buffer containing 0.1% Triton X-100 (KH2PO4-NaOH, pH 7.0)Dilute 20 ml of Triton X-100 solution (C) with approx. 800 ml of 0.01M Phosphate buffer (B). Fill up to 1,000 ml with 0.01M Phosphate buffer (B).E. NADH soluton Weigh 9 mg of NADH and dissolve in 0.1M Tris-HCl bufer (A). Fill up to 50 ml with 0.1M Tris-HCl Buffer (A). (Can be used for 5 days if kept refrigerated)F. Substrate solutionWeigh 11 mg of oxaloacetic acid and dissolve in 0.1M Tris-HCl buffer (A). Fill up to 50 ml with 0.1M Tris-HCl buffer (A) (Make a fresh solution for each use.)G. Enzyme solutionWeigh out Malate Dehydrogenase and dissolve in chilled 0.01M Phosphate Bufer containing 0.1% Triton X-100 (D). Enzyme solution should be prepared so that the value of AOD/minute becomes in the range of 0.025 ± 0.010.ProcedurePipette 2.0 ml of NADH solution (E) and 0.90 ml of Substrate solution (F) respectively into a quartz cell (d=10 mm) and keep at 25 + 0.5'℃ for 5 minutes. Then, pipete 0.10 ml of Enzyme solution (G) into the quartz cell and mix well immediately. Keep the reaction mixture at 25 ±0.5'C.Exaclly at 2 minutes and 5 minutes after the addition of Enzyme solution (G), measure the absorbances of the reaction mixture at 340 nm(A2 and A5).As a blank, pipette 0.01M Phosphate buffer (D) into another quartz cel (d=10 mm) instead of the Enzyme solution (G) and follow the same procedure described above (Ab2 and Ab5).CalculationMalate dehydrogenase activity (u/mg)=[(A2-A5)-(Ab2-Ab5)]/3*(1/6.22)*(n/0.1) ApplicationThis enzyme is used for the enzymatic determination of L-malate and gluamate oxalo-acetate transaminase(GOT)in clinical diagnosis... Read More | Inquire | Inquire |