gRAD Frequently Asked Questions

How long does it take to develop my own assay using a gRAD OneDetection Kit?

To develop your assay, you need a suitable pair of antibodies – a biotinylated capture antibody and a detection antibody to be conjugated with colloidal gold. Both the capture and detection antibodies should specifically recognize the analyte you want to detect. For existing antibody pairs, you should be able to have your first working test on the first day, optimization of the conjugation with gold and development of the assay on gRAD takes approximately two weeks, depending on the experience of the user.


Which size of gold particles should I choose for my gRAD assays?

We recommend comparing the 20 nm and 40 nm particles for your specific application and selecting the size that offers the best performance for your assay. Incident light can be scattered or absorbed by gold nanoparticles. The extinction (sum of scattering and absorption) is predominantly due to absorption on smaller particles and scattering of larger particles. Identifying the optimal size of gold particles may help improve the sensitivity of the assay. Usually, larger particles are more sensitive than smaller particles. But on the other hand, smaller particles have a larger surface area to volume ratio and are coated with less ineffective antibodies.


Can I use polyclonal antibodies with the gRAD OneDetection strips?

Yes. However, all polyclonal antibodies must be affinity purified with the antigen of interest. The use of antisera and protein A and G purified antibodies will result in a poor test response.


Can I use whole blood samples with gRAD OneDetection strip?

The current version of gRAD OneDetection strip is optimized to be used with liquid samples in the form of urine, serum, plasma, water, or solid material dissolved in the sample diluent. To use whole blood, we recommend preliminary sample preparation. Contact us if you are interested in using whole blood or other sample matrices.


Can I use gRAD OneDetection strip with oligonucleotides?

The current version of the gRAD OneDetection strip has not been validated for use with oligonucleotides. The current gRAD OneDetection strip configuration is expected to be compatible to detect PCR reaction products where one primer is biotinylated and the other primer contains another tag, such as a fluorescent label, DNP, or DIG with a specific antibody conjugated to gold, latex or other detection systems.


Can I use gRAD OneDetection kit to develop a quantitative assay?

Yes. For more information and options on how to develop a quantitative assay with gRAD, please contact us.


Can BioPorto Diagnostics help me find the right matched antibody pairs for my assay?

Yes. BioPorto has a portfolio of high-quality matched antibody pairs consisting of a biotinylated antibody and an antibody that can be conjugated with gold.


Does BioPorto Diagnostics provide custom services in assay development with gRAD OneDetection kit?

Yes. We have a long history of listening to our customers and addressing their needs. If you have any special requirements for developing your assays, we will be happy to collaborate with you and set up a solution that meets your needs.


Does BioPorto Diagnostics offer gold-conjugated antibodies?

At the moment BioPorto Diagnostics does not have a portfolio of readily available gold-conjugated antibodies. For assistance in the conjugation of antibodies to gold, please contact us.


Can I apply for the gRAD Partner Program?

The gRAD Partner Program is meant for academic institutions or research centers trying to develop assays based on the gRAD OneDetection kit. The Program offers a collaborative relationship between your institution and BioPorto Diagnostics in order to research and develop new rapid assays. Please contact us for specifics related to qualifying for this program.