For the best experience on the Abcam website please upgrade to a modern browser such as Google Chrome

Hello. We're improving abcam.com and we'd welcome your feedback.

Hello. We're improving abcam.com and we'd welcome your feedback.

Infomation icon

We haven't added this to the BETA yet

New BETA website

New BETA website

Hello. We're improving abcam.com and we'd welcome your feedback.

Take a look at our BETA site and see what we’ve done so far.

Switch on our new BETA site

Now available

Search and browse selected products

  • A selection of primary antibodies

Purchase these through your usual distributor

In the coming months

  • Additional product types
  • Supporting content
  • Sign in to your account
  • Purchase online
United States
Your country/region is currently set to:

If incorrect, please enter your country/region into the box below, to view site information related to your country/region.

Call (888) 77-ABCAM (22226) or contact us
Need help? Contact us

  • My account
  • Sign out
Sign in or Register with us

Welcome

Sign in or

Don't have an account?

Register with us
My basket
Quick order
Abcam homepage

  • Research Products
    By product type
    Primary antibodies
    Secondary antibodies
    ELISA and Matched Antibody Pair Kits
    Cell and tissue imaging tools
    Cellular and biochemical assays
    Proteins and Peptides
    By product type
    Proteomics tools
    Agonists, activators, antagonists and inhibitors
    Cell lines and Lysates
    Multiplex miRNA assays
    Multiplex Assays
    By research area
    Cancer
    Cardiovascular
    Cell Biology
    Epigenetics
    Metabolism
    Developmental Biology
    By research area
    Immunology
    Microbiology
    Neuroscience
    Signal Transduction
    Stem Cells
  • Customized Products & Partnerships
    Customized Products & Partnerships

    Customized products and commercial partnerships to accelerate your diagnostic and therapeutic programs.

    Customized products

    Partner with us

  • Support
    Support hub

    Access advice and support for any research roadblock

    View support hub

    Protocols

    Your experiments laid out step by step

    View protocols

  • Events
    • Conference calendar
    • Cancer
    • Cardiovascular
    • Epigenetics & Nuclear signaling
    • Immunology
    • Neuroscience
    • Stem cells
    • Tradeshows
    • Scientific webinars
    Keep up to date with the latest events

    Full event breakdown with abstracts, speakers, registration and more

    View global event calendar

  • Pathways
    Cell signalling pathways

    View all pathways

    View all interactive pathways

Sodium azide removal protocol

Related

  • Return to the antibody guide
    • Next page: Antibody dilutions and titer
    • Choosing an antibody
      • Antibody storage guide
        • Video protocols library
          • Career-free recombinant antibodies

            ​Detailed procedure for sodium azide removal from antibody solutions. 

            Print this protocol.

            Sodium azide is a preservative used for inhibiting the growth of contaminants, such as bacteria or fungi. However, its presence in antibody solutions can affect the use of the antibody in cell culture assays as it is toxic to cells. It can also interfere with antibody conjugation and inhibits the activity of the enzyme horseradish peroxidase.

            Many Abcam antibody products contain sodium azide, and this information is provided on individual datasheets. If the antibody is used for cell culture assays or conjugation, sodium azide removal from the antibody solution is recommended.

            Alternatively, if you're looking for a ready solution, check out our wide range of carrier-free recombinant antibodies, which are conjugation-ready and free from BSA, sodium azide, and glycerol. 

            The following three procedures can be used to remove sodium azide. 

            Dialysis

            ​A dialysis unit can be used to remove sodium azide from samples of 0.1 mL to 70 mL in volume. This is a semi-permeable membrane available in a wide range of size dimensions and pore sizes. Using a membrane with a pore size cut-off at 10-30 kDa will allow the azide to pass through the membrane but will retain the antibody and other proteins in the solution. 



            The molecular weight of IgG is 150 kDa (IgM is ~600 kDa). The molecular weight of sodium azide is 65 Da. 



            Materials required

            • Dialysis membrane/tubing of appropriate diameter and length to accommodate the sample volume (10–30 kDa molecular weight cut off)
            • Dialysis buffer, e.g. PBS, TBS or HEPES (pH range 6–8)
            • Large beaker
            • Magnetic stirrer at 4°C 
            • Stirring bar​


            Procedure

            1. Assemble the dialysis unit, as recommended by the manufacturer. Pre-condition the unit for a minimum of 1–2 min in the dialysis buffer to allow the membrane to hydrate.
            2. Transfer the antibody solution into the dialysis unit.
            3. Place the dialysis unit into a suitably sized beaker containing at least 1 L of buffer against which the antibody is to be dialyzed. Place the beaker on a magnetic stirrer and dialyze for a minimum of 1 h at 4°C.
            4. Change the buffer and dialyze again for at least 1 h. Repeat until the desired number of buffer changes has been achieved. Ensure that the buffer is changed at least 3 times.


            If possible, all materials should be sterilized and the resulting preparation handled aseptically. Cold conditions are recommended as the antibody is no longer protected by preservative.



            Desalting

            This procedure is suitable for smaller volume of 1–3 mL. Desalting resins have size exclusion properties and consist of small particles with a range of pore sizes.

            Size exclusion is a method used to separate molecules in solution by their molecules in solution by their molecular weight. Particles of varying molecular weight will elute through a size exclusion matrix at different rates. For example, large molecules cannot enter the pores of the matrix and therefore are eluted first, whereas smaller molecules will penetrate the pores within the beads and elute later. 

            A Sephadex G25 column system or equivalent will effectively remove sodium azide from an antibody sample. Pre-packed Sephadex spin columns are readily available and can be used for this procedure.

            Materials required

            • Sephadex G25 spin column 
            • Equilibration buffer
            • Centrifuge


            ​Procedure

            1. If commercially available purification columns are being used, please refer to the manufacturer's instructions for use. 
            2. Remove the cap from the spin column and centrifuge at 1,000 g for 2 min to remove the storage solution.
            3. Put the column in a collecting tube.
            4. Fill the column with equilibration buffer as advised by the manufacturer and centrifuge at 1,000 g for 2 min.
            5. Repeat 3 times and discard the collected flow-through.
            6. Add 1–3 mL of antibody sample slowly to the middle of the packed bed and centrifuge at 1,000 g for 2 min.
            7. Collect and recover the eluate (antibody) located in the collection tube.


            Antibody purification kit

            ​Kits are commercially available for purification of antibodies which can also be used to remove azide.

            The following Abcam kits can be used to purify the antibody from a solution containing BSA, glycine, Tris or sodium azide. It can also be used to purify antibodies from crude samples such as ascites fluid or immune serum.

            The method involves capture of the antibody on a Protein A resin and removal of unwanted substances by a simple wash procedure, which can be performed using a standard microfuge. The purified product is then eluted and neutralized.

            View the datasheet for ab102784 Antibody purification kit (3 X purification).

            Get resources and offers direct to your inbox Sign up
            A-Z by research area
            • Cancer
            • Cardiovascular
            • Cell biology
            • Developmental biology
            • Epigenetics & Nuclear signaling
            • Immunology
            • Metabolism
            • Microbiology
            • Neuroscience
            • Signal transduction
            • Stem cells
            A-Z by product type
            • Primary antibodies
            • Secondary antibodies
            • Biochemicals
            • Isotype controls
            • Flow cytometry multi-color selector
            • Kits
            • Loading controls
            • Lysates
            • Peptides
            • Proteins
            • Slides
            • Tags and cell markers
            • Tools & Reagents
            Help & support
            • Support
            • Make an Inquiry
            • Protocols & troubleshooting
            • Placing an order
            • RabMAb products
            • Biochemical product FAQs
            • Training
            • Browse by Target
            Company
            • Corporate site
            • Investor relations
            • Company news
            • Careers
            • About us
            • Blog
            Events
            • Tradeshows
            • Conferences
            International websites
            • abcam.cn
            • abcam.co.jp

            Join with us

            • LinkedIn
            • facebook
            • Twitter
            • YouTube
            • Terms of sale
            • Website terms of use
            • Cookie policy
            • Privacy policy
            • Legal
            • Modern slavery statement
            © 1998-2022 Abcam plc. All rights reserved.