[pushkins]

The Kilz will cover the cat stain and help "mask" the smell, It will not water proof the concrete.

My point with the plastic test wasn't to assure you that if you did it and found no readily see able moisture that you would be safe to install laminate flooring in your basement.
Moisture doesn't have to be seen to be there, the basement floor is touching earth, the earth is always wet (varying degrees of wetness), concrete is porous, concrete absorbs moisture.

Again I reiterate, The manufacturers give no warranty for laminate flooring installed below grade ie: basements, there is a simple reason why and that reason is summed up in three words ....."moisture" and "product failure".