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Streptavidin FAQs

1. What is the best storage condition for the kit?

The kit is shipped at ambient temperature and its components need different storage temperatures. Upon arrival, the plastic pot containing the strips, manufactured with molecular sieves integrated into the walls, must be kept at 4⁰C. The lyophilized control vial must be stored at -20⁰C; once reconstituted, the Rabbit IgG-Streptavidin conjugate is stable at 4⁰C for up to 1 year in the 1x Running Buffer + BSA. The lyophilized 40nm InnovaCoat® GOLD Biotin must be stored at -20⁰C; once reconstituted it is stable at 4⁰C for up to 2 weeks. Keep the 10x Running Buffer at 4⁰C.

2. Can antibodies from different species be used?

Yes, the Protein A/G strips have been tested with antibodies from a variety of species including mouse, rabbit, goat and rat, providing they are conjugated to a colored label. The binding properties of Protein A and G, immobilized on the Test line of the strips, differ among species and subclasses of IgG. A low or no affinity for a specific IgG subclass may lead to low/no signal but the conjugate may be still fine. Affinity of Protein A and G for different Ig subclasses is reported in the table below.

3. Can conjugates from antibody fragments be checked?

The protein A and protein G immobilized on the Test line have a high affinity for the Fc region of IgG molecules, and therefore for the Fc fragments as well.

4. Can I use the Streptavidin Check&Go! kit to confirm successful conjugation of my antibody to other labels?

Streptavidin Check&Go! can only be used to check whether or not your Streptavidin conjugation has been successful however we do provide another kit that enables the detection of antibody conjugation to fluorescent dyes and proteins, latex beads and gold nanoparticles. Find out more about this product here.

5. Can I use the Streptavidin Check&Go! kit to quantify the level of streptavidin conjugation?

No, you can’t.Streptavidin Check&Go! is a rapid qualitative method. However, you can discriminate different degrees of biotinylation based on the line intensity of your diluted conjugate.

Please see here for ordering & shipping information.

SpeciesIg Sub classes
Binding to Protein A

Binding to Protein G



RabbitIgGHighHigh
HumanIgG1HighHigh
IgG2HighHigh
IgG3No affinityHigh
IgG4HighHigh
IgALowNo affinity
IgDLowNo affinity
IgELowNo affinity
IgMLowNo affinity
PigIgGHighHigh
MouseIgG1Low/Medium
Medium
IgG2aHighHigh
IgG2bHighMedium
IgG3Low/MediumMedium
IgMLowNo affinity
GoatIgGLowHigh
SheepIgGLowHigh
RatIgGLowHigh
IgG1LowLow/Medium
IgG2aLowHigh
IgG2bLowLow/Medium
IgG2cLowLow/Medium
IgMLowNo affinity