A mixing bag having an interior mixing chamber having a volume sufficient to receive a predetermined weight of substantially dry material and a selected volume of process compatible solution to form a solution having the material in suspension with a selected concentration is shown. The mixing bag includes at least two sealable openings. One opening is configured for at least one of enabling transporting the substantially dry material into the interior mixing chamber, enabling agitation of the material and process compatible solution in the interior mixing chamber to form the solution and enabling withdrawal of the solution at the selected concentration. The other opening is configured for at least one of injection of a process compatible solution into the interior mixing chamber to form the solution, enabling agitation of the material and process compatible solution in the interior mixing chamber and enabling withdrawal of the solution.