Antibody storage guide!
1. After receiving the antibody, be sure to centrifuge it at 12,000 rpm for 20-30 s before opening the tube cover for aliquots and storage!
High-quality antibodies use very special storage tubes. Only centrifugation at 12,000 rpm for 20-30 s can remove all antibodies attached to the tube wall or cap. Even centrifugation at 10,000 rpm will result in incomplete centrifugation, resulting in insufficient amounts of antibodies!
2. For most antibodies, the more appropriate storage method is to aliquot and store at -20 degrees or -80 degrees. For most antibodies, storage at -20 degrees is completely sufficient. There is no evidence that storing at -80 degrees would have any benefit!
Aliquoting can minimize the damage to antibody activity caused by repeated freezing and thawing, and also reduces the possibility of contamination caused by drawing antibodies from the same tube multiple times.
The amount of aliquots should be used up in one experiment, and should not be less than 10ul per portion. Because the smaller the aliquot volume, the concentration of the antibody is more likely to be affected by evaporation and adsorption on the tube wall.
If the re-melted aliquoted antibody cannot be used up at one time, store the remaining mother solution at 4 degrees to avoid freezing it again!
The antibody working solution should be prepared and used up on the same day, and try not to exceed 1 day at 4 degrees Celsius.
Definitely avoid storing antibodies in self-defrosting refrigerators. Try to store antibodies on the inside of the refrigerator, not on the door.
3. Short-term storage of most antibodies at 4
°C for 1-2 weeks after receipt will have no effect on the activity of the antibodies.
If the antibody will be used soon (1-2 weeks), it is recommended to store it at 4 degrees Celsius to avoid damage to the activity of the antibody caused by repeated freezing and thawing. If you want to store it for a long time, it is best to store it at -20 degrees or -80 degrees. The most critical point is to store the antibody correctly according to the method recommended in the instructions! However, please freeze products in ascites form immediately upon receipt! Because this type of product contains a large amount of protease, long-term storage at 4 degrees Celsius will cause the degradation of the antibody!
4. Shipping conditions for most antibodies: The general shipping process takes 1-2 weeks, so it is completed at 4 degrees.
The main purpose of 4-degree transportation is to avoid damage to antibody activity caused by repeated freezing and thawing (if dry ice is used for transportation, the antibody will be frozen when received and needs to be thawed for packaging. This requires an additional freezing and thawing process. ). So absolutely avoid dry ice transportation during transportation!
Storage conditions for special antibodies:
1. Enzyme-linked antibodies: Always store at 4 degrees and avoid freezing. Otherwise, the enzyme activity will decrease or be lost.
2. Conjugated antibodies: All conjugated antibodies are stored in brown tubes or using tin foil to protect from light. Especially fluorescent antibodies are extremely sensitive to light, so they must be operated away from light during all experimental stages!
3. IgG3 isotype control: Always store at 4 degrees and avoid freezing. This is because the antibody can easily form multimers if there is a freezing and thawing process.
Whether storing or transporting, absolutely avoid repeated freezing and thawing! Repeated freezing and thawing will cause the denaturation of the antibody, leading to the formation of polymers, thereby reducing the binding ability of the antibody!
Other related information about antibody storage:
Regarding adding glycerol for storage: Some people will add 50% glycerol to the antibody to avoid repeated freezing and thawing. Glycerin will lower the freezing point at -20 degrees.
This may be feasible for many antibodies. However, abcam has only tested the stability of a very small number of antibodies under such conditions; and abcam only provides quality assurance for antibodies stored under recommended conditions! It is not recommended to store solutions containing glycerin at -80 degrees as this has exceeded the freezing point of glycerol. If you want to add glycerol to preserve antibodies, please pay careful attention to aseptic operation to avoid contamination!
About protein protectant:
Protein is less likely to degrade at high concentrations (1 mg/ml or higher), which is why BSA and the like are added to the antibody as a stabilizer; on the other hand, the added protein can also reduce the risk of the antibody being damaged by the tube wall losses caused by adsorption. However, if the antibody is to be used for labeling, protein stabilizers cannot be added because these stabilizers will compete with the antibody for binding to the label.
Regarding the use of sodium azide:
To prevent microbial contamination, sodium azide is often added to antibodies (final concentration 0.02% (w/v)). Many of Abcam's antibodies already contain 0.02%-0.05% sodium azide, which is indicated in the "Storage buffer" in the instructions.
Sodium azide should not be used in the following situations:
(1) If the antibody is used to stain or treat living cells for in vivo studies:
While sodium azide is resistant to microorganisms, it is also toxic to most other organic matter because it blocks mitochondrial
cytochrome electron transport system.
(2) To couple antibodies with amino groups:
Sodium azide will interfere with any coupling containing amino groups, so it should be removed before coupling. Coupled antibodies can be preserved by adding sodium azide, but the concentration can only be 0.01%. For antibodies that require conjugation, thimerosal (merthiolate) can replace sodium azide as a protective agent!
Note: How to remove sodium azide:
It can be removed by gel electrophoresis or filtration! The molecular weight of IgG is 150 kDa (IgM is ~600 kDa); the molecular weight of sodium azide is only 65 Da. Sodium azide can be removed from the antibody using a cut off 14 kDa filter.
