Serum operation is always seen as a difficult task in practical experiments and many scientists have made great efforts in discovering more effective methods to solve the problem. Given the fact, common problems for serum operation should be payed enough attention.
1. The best way to preserve serum
We recommend that serum should be stored at -5℃ to -20℃. If you can not run out of a bottle, you should aseptically package the serum into a appropriate sterile container, and then put back into the freezer.
2. How to thaw the serum without damaging the quality of products?
We recommend that you should first dissolve it in the refrigerator (usually at 2-8 ℃) after removing the serum from freezer. Then, it is the whole solution at room temperature. It must be noted that the dissolution process should be dealt regularly.
3. How to deal with the problem after thawing serum with flocculent precipitate?
Serum precipitate occurs for a number of reasons, but the most common reason is due to the degeneration of serum lipoproteins. And fibrin (one protein coagulation) will exist in the serum after the serum is thawing. It is also one of the main causes of serum precipitate. But the flocculent precipitate does not affect the quality of the serum itself. Maybe some other chemical substances require the process too, such as hexapeptide.
If you want to remove the flocculent precipitate you can dispense the serum into a sterile centrifuge tube and centrifuged slightly to 400g; the supernatant can be followed along the inner filter media. We do not recommend you to remove the flocculent precipitate through filtration, because it can clog your filter membrane.
4. What is heat-inactivated process? Is it necessary to do this?
Thawed serum should generally be processed at 56℃ for 30 minutes because this heating step can make the complement lose the activity. In terms of the involved complement reactions, they generally means the release of cytolytic activity, contraction of smooth muscle, mast cells and platelets histamine, enhanced phagocytosis, chemotaxis and activation of lymphocytes and macrophage.
Experiments show that heat-inactivated serum after handled correctly is unnecessary for most of the cells. In addition, processed serum could only slightly promote the cell growth, or absolutely no obvious effect. Sometimes, because the high temperature usually affects the quality of serum, the cell growth rate might decrease apace. In brief, precipitate formation requires more attention.
5. How to avoid sediment?
We recommend you to pay attention to the right thawing steps while using the serum, and try to avoid prolonging the inactivated process of serum or placing serum in high temperature environments.
To be honest, serum operation has been constantly helpful in biotechnological areas, such as cell research and peptide synthesis so that it’s necessary to improve related measurement process. Briefly, biotech has developed rapidly, so it demands sort of overall progress. Serum operation is one of the kind.