• Which type of target molecules can be used?
• Which type of plates and strips should I use in the different detection methods?
• Should I optimise the concentration of the target molecule?
• Why should I pre-wash before use?
• What is the binding capacity?
• For how long should I incubate the biotinylated target molecule with the streptavidin surface?
• For how long are the plates stable?
• Why am I getting a high background signal?

Which type of target molecules can be used?
When working with the Nunc Immobilizer™ Streptavidin instant coupling of biotinylated bio-molecules will occur. The Nunc Immobilizer™ Streptavidin is especially designed and optimised for detection biotinylated nucleic acids, peptides, and proteins.

Which type of plates and strips should I use in the different detection methods?
We recommend using transparent polystyrene plates and strips for colorimetric assays, white polystyrene plates for bio- and chemiluminescence assays and black polystyrene plates for fluorescence assays.

Should I optimise the concentration of the target molecule?
Yes. We recommend that the amount of target molecule is optimised. Initially, we suggest the following:
Biotinylated nucleic acids: 0.5 µM – 0.01 µM diluted in 5 x SSCT buffer pH=7.0
Biotinylated peptides: 1 µg/ml – 1 ng/ml diluted in a PBST buffer pH=7.2
Biotinylated proteins: 5 µg/ml – 0.05 µg/ml diluted in a PBST buffer pH=7.2

Why should I pre-wash before use?
It is highly recommended to pre-wash the Nunc Immobilizer™ Streptavidin. This will ensure improved readouts and a very low coefficient of variation (CV%≤ 5) from plate to plate and from well to well.

What is the binding capacity?
Total binding capacity for free biotin is:
20 pmol/well in a 96 well (coating volume 100 µl)
10 pmol/well in a 384 well (coating volume 50 µl)

For how long should I incubate the biotinylated target molecule with the streptavidin surface?
Coupling of the target molecule to the streptavidin proceeds very fast. Results show that incubation with gentle agitation for 2 hours at room temperature ensures that all available active sites are saturated.

For how long are the plates stable?
The Nunc Immobilizer™ Streptavidin plates and strips are extremely stable over time, if stored at room temperature (20-25°C). Nunc guarantees 18 months shelf life in unopened foil package after the date of manufacturing.

Why am I getting a high background signal?
The reason could be inadequate washing. Make sure to pre-wash the plates and increase the number of washing steps and the time between washes. The reason could also be too high a concentration of the detection components.