If you require or would like to use a mix of different lot numbers for solutions from the MicroSolv HSQ™, UV-vis™ or PQ™ Kit solutions, this is an acceptable protocol under some conditions: You cannot mix different lots among the L1-L6 solutions. These solutions are for UV detector linearity and are designed to be used as a set. However, you can for example use one lot for the linearity solutions and another for the HOX solution.
This may be the case if for example you have one solution with a longer expiration date than the others. Ordinarily this would not occur if all the solutions in the kits are used together, as the solutions normally all have the same expiration date in the same kit.