The suitability of five liquid scintillation cocktails for use with a continuous flow-through mucosal perfusion system.

Continuous flow-through perfusion systems can be successfully used to study the permeability of small mucosal samples to various permeants. The latter often need to be radiolabelled to enable detection by means of liquid scintillation counting. However, the efficacy of the latter is dependent on the liquid scintillation cocktail used. The present study was conducted to evaluate five liquid scintillation cocktails commercially available in South Africa. Although four out of the five cocktails had similar efficacies in the concentration range 0.05 to 50 nCi, this was not the case in the low range (0.01 to 0.5 nCi). Overall Ready Protein+ was the most efficacious and has the added advantage that this cocktail has protein solubilising properties. The latter is important when we extend our permeability studies to include small proteins.