Depending on the particular test being performed, the laboratory may make use of one or several of these examples to demonstrate that the test or examination/analysis is "under control". The quality control procedures necessary in any particular area of work should be determined by the laboratory responsible for the work, based on best professional practice. The procedures should be documented and records should be retained to show that all appropriate QC measures have been talen, taht all QC results are acceptable or, if not, that remedial action has been taken.