Unfortunately, once the Qubit Protein Reagent (Component A) is mixed with the Qubit Protein Buffer (Component B), it is not recommended to store the working solution for later use. The Qubit Protein Assay reagents are designed for immediate use after mixing, and their stability is optimized for single-use reactions. Storing the mixed solution can result in degradation of the reagents and inaccurate protein quantification.

If you find yourself in a situation where you have prepared more reagent than needed, it’s best to discard the leftover mixed solution and prepare a fresh batch for future experiments. For accurate results, it's crucial to use freshly prepared reagent solutions.