Yes, all of our reagents include in ToxiLight™ Non-Destructive Cytotoxicity BioAssay, the ViaLight™ Plus BioAssay, the MycoAlert™ and MycoAlert™ Plus Assay, the PPiLight™ Inorganic Pyrophosphate Assay and the PDELight™ HTS cAMP Phosphodiesterase Assay Kit the should not be exposed for extended periods to light, it is advisable to keep them covered. If they are in a trough on ice, simply covering with aluminium foil should be sufficient.