We know that both monoclonal and polyclonal antibodies are critical elements in your investigations, so it is important to take extra care so that their function is not lost.
Although they are generally resistant elements, we need to take into account a series of steps to fully preserve their properties.
We leave you some suggestions and tips to keep monoclonal and polyclonal antibodies in the best conditions before starting your experiment and so make sure you get the best of the results:
- READ THE PRODUCT DATA SHEET WELL.
The data sheet contains very useful information on how the antibody should be preserved, the main applications of the particular monoclonal or polyclonal antibody that you have chosen for your experiment, the appropriate dilutions or concentrations for these different applications, etc. They also often include some previous studies where that antibody has been used.
- ELIMINATE UNWANTED REMAINS OF THE ROADS.
As we have commented, in the technical sheet you will find all the information to keep monoclonal and polyclonal antibodies in the best conditions, but before storing them, it is also usually recommended to invert the content of the same and centrifuge it briefly at low speed to collect any liquid that may be found. on the sides of the vial or even on the cap.
- ENSURE THE PROPER STORAGE CONDITIONS.
The shelf life of the antibodies depends on their nature and storage conditions.
Storage at room temperature can cause degradation or even inactivation of the antibody, normally due to bacterial growth.
In our entry “How to store the antibodies” you have more detail about the storage of them, as a reminder and extension of some details:
To avoid microbial contamination, sodium azide can be added to an antibody preparation at a final concentration of 0.02% (w / v). Although many antibodies already contain this preservative in concentrations ranging from 0.02 to 0.05% (this will be indicated in the data sheet in the storage buffer section).
In case your experiment requires staining or treating living cells with antibodies, or if you use monoclonal or polyclonal antibodies for in vivo studies, make sure to use preparations that do not contain this sodium azide, since this antimicrobial agent is toxic to many organisms: it blocks the electron transport system of cytochrome.
Another important exception are those HRP-conjugated antibodies that should not be stored in buffers containing sodium azide, since it inhibits HRP. An acceptable alternative is 0.01% thimerosal (merthiolate) that does not have a primary amine.
Certain antibodies, such as fluorescent ones, are particularly prone to photobleaching and therefore must be stored protected from light at all times, even during experiments.
It is possible to preserve monoclonal and polyclonal antibodies in the long term at temperatures below zero (-20ºC or -80ºC). However, the preservation of the antibody will also depend on the frequency of its use. For example, if you are going to use the antibody once or twice a week in the design of your experiment, it is better to keep it at 4ºC during this time.
It is important to try to avoid damage by freezing or thawing your antibody. As you already know, these frequent freezing and thawing cycles can denature it.
On the other hand, it is important to note that the freezer in which you store the antibody can also affect its stability. Freezers with a frost-free system alter their freezing and thawing cycles, which can damage the antibody you are going to use.
For those long-term antibodies, it is also recommended to aliquot them in tubes with low affinity to the membrane with a range between 10 and 50 µl, and keep them in their concentrated form, since the diluted monoclonal and / or polyclonal antibodies lower their effectiveness.
- TEST THE ANTIBODY UNDER SPECIAL CONDITIONS BEFORE THE REAL EXPERIMENT.
It is good to optimize the antibody to your needs before starting your experiment. Although it is not the fastest way to obtain results, it is the best way for those who obtain to be good.
To determine the optimal concentration for your samples, the data sheet usually provides the recommended concentration at which the antibody works best in most cases. However, if you have special experimental conditions, it is better to confirm this by titrating the antibodies.
Furthermore, it is important to confirm whether the monoclonal or polyclonal antibody is suitable for the intended use: the antibodies are tested in specific applications before being sold but the same antibody may work for other applications. If you are using an antibody for an application that has not been recommended, a thorough check is necessary. Be sure to include adequate controls such as specific negative controls such as samples that do not express your target protein.