Sampling with blood collection tubes

Order of sample collection

Order of sample collection (order of draw) when collecting multiple tubes from the same puncture

  • Cap colour indicates type of chemical inside the tube which keeps the blood in the state needed for testing e.g. promote clotting or prevent the blood specimen from clotting
  • With capillary blood sampling, the haematology specimen is collected first1 followed by chemistry and blood bank specimens2
  • Maintaining the correct order of draw is essential to avoid clot formation and platelet clumping1 which would invalidate the test
Cap colour indicates the type of chemical inside the tube which keeps the blood in the state needed for testing. The colours are universally consistent. The pink and lavender caps are used for Haematology specimens. The green, red and gold caps are used for Blood Chemistry.


When collecting multiple tubes for testing, the order of draw is essential

These materials have been produced in consultation with key opinion leaders and follow global guidelines, but the user should use his or her professional judgement when using any technique or method described in these materials and should take into account all applicable national, regional and institutional guidelines and regulations.

1. Clinical and Laboratory Standards Institute (CLSI) document GP42-A6 (former H04-A6): Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard – Sixth Edition. Clinical and Laboratory Standards Institute; Wayne, Pennsylvania, USA: 2008. 2. WHO guidelines on drawing blood: best practices in phlebotomy. World Health Organisation; 2010.