Question:

On 5th July 2004 we purchased CMV lysate CV001-1 from Virusys. It was made up as per protocol into a stock solution and frozen in 0.1ml aliquots at a concentration of 530uG/ml.

I want to dilute it into a working solution at a concentration of 30ug/ml into 0.1 ml aliquots. However we are concerned about the warning not to freeze-thaw the CMV lysate. Do you think that it is alright to thaw this to dilute it and refreeze it? It will only be one extra freeze thaw cycle, and we can thaw and aliquot the solutions on ice.

Resolution:

One or two quick freeze-thaws will probably not result in too much activity loss. What worries me more is your intent to dilute it prior to re-freezing.

As a general rule, it is not good to dilute and freeze. Any activities of this sort will need to be evaluated in your lab with your assay system in order to determine the ultimate effect.