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streptavidin beads

Developing a Chemiluminescent Immunoassay in Eight Basic Steps

When developing and using a CLIA, it is important to follow eight basic steps in order to ensure that your assay will be the most efficient and accurate that it can be. Whether we are using magnetic streptavidin beads or another type of beads, these are the steps we must follow.

This post is about using magnetic beads, such as streptavidin beads, in Chemiluminescent immunoassays. If you are interested in this topic, download our free ebook The Basic Guide for the use of Magnetic Bead in Chemiluminescent immunoassays:

Free PDF guide:  "The Basic Guide for the use of Magnetic Bead  in ChemiLuminiscent ImmunoAssays (CLIA)" 

1. Define the expected dynamic range

It is important to figure out the approximate concentration range of the analyte in your sample. In addition, you need to figure out what the optimal concentration range is recommended in order to detect your desired analyte. If analyte concentrations are high, you may not need to use such a sensitive technique as CLIA.

2. Define the assayed specimen

The type of specimen  (e.g. blood, serum, urine, etc.) will help you understand the expected dynamic range of analyte contained within the specimen. Therefore, it is important to know what type of specimen you will be working with when analyzing an analyte.

The antibodies attached to streptavidin beads are a key factor in CLIA

3. Select the antibodies to be used in the assay

You will want to select antibodies that are highly specific for your unique analyte. Specificity is key to the success of your assay. Polyclonal vs. monoclonal is important to determine as well and will depend on the character of the antibody itself and how specific each are for your analyte.

4. Choose your best magnetic beads

You will need to determine what the optimal bead size, bead surface area and iron oxide content needs to be for your specific analyte assay.

5. Optimize the coating procedure

When coating your beads, you will want to take into account the adsorption properties of the beads, any covalent binding you will need to create and the biological effects of linking proteins to your beads, or if you will need bio-activated ones, as Protein A or Streptavidin beads.

6. Select your homogenization method

Your choice of homogenization will depend on the equipment you have, the personnel who work on the equipment, the size of your samples and the ease of use within the assay. Your choices are roller homogenization, overhead homogenization, vortexing or sonication.

7. Select the correct biomagnetic separation technology

This technology helps removing free antibodies and other contaminants. In other words, this step reminds you that you need to use systems that have been tested with other beads. Systems that can help you easily validate your process and can help you scale up your process are preferred.

8. Enhance your immunoassays when required

If you can make your assay better, it is important to do so. Making your assay more efficient, more accurate and easier to perform is important not only to the final results of your analysis, but also to the bottom line of your company.

It is vital to remember that all of these steps are important. You should not skip even one step in this process of developing your CLIA.

Don’t forget to check these posts from our blog in order to get a deeper insight into Chemiluminescent immunoassays:

BIO Dr. Fabrice Sultan

streptavidin beads ebook

Lluis M. Martínez | SEPMAG Chief Scientific Officer

Founder of SEPMAG, Lluis holds a PhD in Magnetic Materials by the UAB. He has conducted research at German and Spanish academic institutions. Having worked in companies in Ireland, USA and Spain, he has more than 20 years of experience applying magnetic materials and sensors to industrial products and processes. He has filed several international patents on the field and co-authored more than 20 scientific papers, most of them on the subject of magnetic particle movement.

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