The invention relates to a method, a device and a system for the treatment of biological frozen samples using plasma focused ion beams (FIB). The samples can then be used for mass spectrometry (MS), genomics, such as gene sequencing analysis or next generation sequencing (NGS) analysis, and proteomics. The present invention particularly relates to a method of treatment of at least one biological sample. This method is particularly used for high performance microscopy, proteomics analytics, sequencing, such as NGS etc. According to the present invention the method comprises the steps of providing at least one biological sample in frozen form. The milling treats at least one part of the sample by a plasma ion beam comprising at least one of an O+ and/or a Xe+ plasma.