Storage temperature and conditions
For many of our antibodies, aliquoting and freezing at -20oC or -80oC are the best storage conditions. Dispense into small aliquots to minimize damage caused by freeze-thaw and contamination caused by multiple pipettings from a single reagent bottle. Small aliquots only need to be frozen and thawed once. If left, the remainder can be stored at 4oC. When the antibody is received, centrifuge at 10,000 × g for 20 seconds to deposit the solution trapped in the reagent bottle thread, and take small aliquots Transfer to a low protein binding microcentrifuge tube. The amount of the small aliquot depends on the amount usually used by the experimenter in the experiment. Small aliquots should be no less than 10 µl; the smaller the aliquot, the greater the impact of the stock solution concentration due to antibody evaporation and adsorption to the surface of the storage bottle.
In most cases, it is acceptable to store the antibody at 4oC for one to two weeks after receiving the antibody, and then freeze it for long-term storage, but perhaps ascites fluid is the exception. It may contain proteases and should be frozen as soon as possible. Again, it is important to follow the recommendations on the data sheet.
Disclaimer and other special conditions:
Enzyme-coupled antibodies should not be stored frozen, but should be stored at 4oC. Freezing and thawing not only affects antibody binding capacity, but also reduces enzyme activity.
Whether coupled to fluorescent dyes, enzymes, or biotin, conjugated antibodies should be stored in dark reagent bottles or wrapped in metal foil. Exposure to light will damage the activity of the conjugate. Especially fluorescent conjugates are susceptible to photobleaching and should be protected from light at all stages of the experiment.
IgG isotype antibody 3 has a unique tendency to form aggregates upon thawing and should always be stored at 4oC.
Prevent pollution with sodium azide
To prevent microbial contamination, sodium azide can be added to antibody preparations to a final concentration of 0.02% (w / v). Many Abcam antibodies already contain this preservative. Antibodies already contain this preservative in concentrations ranging from 0.02 to 0.05%. This will be marked on the data sheet under the heading "Save Buffer".
When not using sodium azide:
If staining or treating live cells with antibodies, or if conducting in vivo studies with antibodies, be sure to use preparations that do not contain sodium azide. The antibacterial agent is also toxic to most other organisms: it blocks the cytochrome electron transport system.
Sodium azide interferes with any coupling in which the amino group participates, and should be removed before the coupling proceeds. After coupling, the antibody can be stored in sodium azide. In addition, 0.01% thimerosal (thimerosal) does not contain primary amines and is also an acceptable substitute
Sodium azide can be removed from the antibody solution by dialysis or gel filtration. The molecular weight of IgG is 150,000 Daltons (IgM is about 600,000); the molecular weight of sodium azide is 65 Daltons. A microdialysis device with a molecular weight cut-off of 14,000 Dalton retains the antibody while allowing the azide to diffuse out. In a beaker maintained on a magnetic stirrer at 4oC, use at least one liter of cold PBS per ml of antibody and stir the dialysis device for 6 hours. Change the PBS twice, stirring for at least 6 hours each time. If possible, all materials should be sterilized and the resulting preparation should be handled aseptically.
Freeze / thaw damage
Repeated freeze / thaw cycles can denature the antibody, causing it to form aggregates that reduce the antibody's binding capacity.
Storage at -20oC is appropriate for most antibodies; storage at -80oC has no obvious advantages. The refrigerator cannot be frost-free. These cycles between freezing and thawing (to reduce frosting) are precisely what should be avoided. For the same reason, antibody reagent bottles should be placed in the refrigerator area with minimal temperature fluctuations, for example toward the rear of the refrigerator rather than on the door shelf.
Some researchers have added the cryoprotectant glycerin to a final concentration of 50% to prevent freezing / thawing damage; glycerin can lower the freezing point below -20oC. Although this is acceptable for many antibodies, only a small portion of the antibodies we provide tested for stability under this storage condition, and our warranty only applies to antibodies stored in the manner recommended on the data sheet. It is not recommended to keep the solution containing glycerin at -80oC because the temperature is lower than the freezing point of glycerin. Please note that glycerin can be contaminated by bacteria. If glycerin or any cryoprotectant is added, care should be taken to obtain a sterile preparation.
It should be avoided to store the antibody at 4 ° C for more than one day after dilution to working concentration. Proteins are generally not easily degraded when stored at high concentrations. The ideal concentration is 1 mg / ml or higher. This is the theoretical basis for adding proteins such as BSA as a stabilizer to the antibody solution. The added protein also helps reduce the loss of antibodies caused by binding to the walls of the container. For antibodies intended to be conjugated, stable proteins should compete with antibodies and reduce the efficiency of conjugation, so stable proteins should not be added
Kids's Furniture Handles,Kids Plastic Knob,Kids Door Handle,Kids Coloful Handles
Shenzhen Hongjingyuan Metal&Plastic Products Co., Ltd. , https://www.hjypull.com