Mixer Mill MM 400 - RETSCH - powerful grinding by impact ... Retsch, Milling, Sieving, laboratory equipment, lab mill, jaw crushers, sieve shakers The mixer mill MM 400 is a compact versatile bench-top unit, which has been developed specially for dry, wet and cryogenic grinding of small amounts of sample. It can mix and homogenize powders and suspensions in only a few seconds. It is also perfectly suitable for the disruption of biological cells as well as for DNA/RNA and protein extraction.