Substrate Assays
➦ PortaCellTec offers three possibilities to measure substrate transporter interaction:
- Quantification of substrate uptake with a radio-labeled substrate
- Quantification of substrate uptake with a fluorescent substrate
- Quantification of non-labeled substrate uptake by LC-MS (we provide this service together with a cooperation partner).
How to identify a test item as a substrate for one specific transporter?
- Test item uptake in transporter-HEK cells is more than 2fold higher than in control-HEK cells.
- Significant inhibition of the transporter mediated test item uptake by a known probe inhibitor.
A two-step experimental setup
First Step
Time and concentration dependent uptake of a test item is performed in the absence and presence of a probe inhibitor.
Second Step
Determination of Km and Vmax value: Concentration dependent uptake of a test item to determine the affinity (Km value) and the maximum transport rate (Vmax) of a transporter for a test item.
