Troubleshooting Enzyme Immunoassays

Problem: Substrate module loses reactivity after being opened or used once.


Possible Causes:

1. Substrate modules are packaged with desiccant packets and their stated shelf life depends upon proper storage. If the entire 96 well module is not required for the day's assay, remove the required strips after the package has been allowed to reach ambient temperature. This will avoid immediate condensation onto the strip wells. Immediately reseal the packaging and return to storage temperature.

The optimal storage of modules, once opened, is within a desiccant jar under refrigeration. Modules are currently shipped in resealable packages with 2 x 2 gram desiccant packets. This resealing feature is dependent upon the status of the desiccant packets, however, as current technology for resealable packaging is not completely dependable. Desiccant jars are still a better guarantee of a long shelf life.