ISO 13079:2011 specifies requirements for single-use and re-usable glass and plastics tubes for measuring the erythrocyte sedimentation rate (ESR) by the Westergren method, and for a support to hold tubes during the performance of the test. These so-called "Westergren tubes" are also sometimes designated as "Westergren pipettes". A procedure for measuring the erythrocyte sedimentation rate by the Westergren method is given in an informative annex.