Frequently Asked Questions(FAQ)

Q: What is the shelf life of InvivoCrown antibodies ?

InvivoCrown does not limit the shelf life of any antibody by providing an expiration date. Store at 2 to 8°C for at least 2 months. Aliquot in working volumes without diluting and store at -20°C or -80°C for twelve months from the date of receipt. Avoid repeated freeze thaw cycles.

Q: What's the best way to dilute my antibody?

We recommend diluting our antibodies in the InVivoPro dilution buffer matching the pH that the antibody is supplied in. In the absence of the recommended InVivoPro dilution buffer, sterile 1x PBS matching the exact pH of the antibody formulation can be used. It is important to match the pH of the dilution buffer to the antibody solution to avoid aggregation. When diluting we recommend using cold buffer and maintaining sterility by working in a biological safety cabinet and using sterile pipet tips, tubes, syringes, and buffers. Diluting antibodies to working concentrations and storing at 4°C for more than a day should be avoided.

Q: Why are there precipitates in my antibody solution?

Environmental conditions such as temperature variations, freezing/thawing, shaking during transport, and long-term storage might lead the appearance of a precipitate or floccule in the antibody solution. This is not uncommon. The floccule is typically buffer salts precipitating out of solution or a small bit of protein aggregation. If gentle, repeated inversion of the vial does not remove the precipitate, we recommend removing the floccule by filtration. We recommend using a sterile 0.2μM luer lock syringe filter for filtration. It is important that you should use sterile filters, syringes, tubes, etc. and work in a biological safety cabinet to ensure that the solution remains sterile.

Q: How do you measure the antibody concentration?

We measure antibody concentration via absorbance @280 nm using an extinction coefficient of 1.33. When determining the concentration of our antibodies, we first mix 100μL of the stock antibody solution with 1.9 mL of pH matched PBS (1:20 dilution). We then take the A280 reading (after the spec has been blanked against our pH matched PBS), multiply it by 20 (as this is our dilution factor) and then multiply by 0.75 (which is the result of 1/1.33).

Q: What is the amino acid or DNA sequence of the antibody?

Our antibodies are produced using standard hybridoma technology and so the AA or DNA sequence of the antibody is usually unknown.

Q: What is the epitope of the antibody?

We have not epitope-mapped our antibodies at InvivoCrown. The antibody is usually generated using the entire immunogen included on the data sheet.

Q: What is the in vivo half-life of your antibody?

We do not have direct experimental data generated at InvivoCrown concerning the half-life of our antibodies in vivo. Antibody half-life can be highly variable and influenced by a variety of factors including species, isotype, antigen distribution, antigen concentration and many others.

Q: How do I choose the proper isotype control antibody?

Incorporating an isotype control treated group is required to generate reliable data because it allows the researcher to accurately differentiate between results observed from primary antibody binding in an antigen-specific manner and results observed from non-antigen specific binding or other nonspecific effects of antibody injection. The isotype control antibody must match the host species, isotype, and subclass of the primary antibody.

Q: What dose or frequency of administration should I use to treat my mouse?

The optimal dose and frequency of administration for any given experiment and antibody can vary greatly depending on the experimental system (i.e. mouse strain, disease model, etc.), the duration of the experiment, the target tissue, the antigen concentration, and many other details. For this reason, the optimal dose is best determined by reading through the product references associated with the antibody you’re interested in to find published data in an experimental system similar to yours. Using this existing research as a starting point, you can then optimize the dose and frequency of administration experimentally. Or you can also contact our technical team. They will refer to some references to provide you with information for reference.