Storage and transport of capillary blood specimens
Maintaining specimen quality during storage and transport
- Always consult institutional guidelines for storage and transport recommendations for the test being collected before beginning the procedure
- Specimen storage requirements may depend on the type of collection tube, test being performed and testing instrumentation
- Storage conditions may affect specimen stability1 and result accuracy; prolonged or incorrect storage may affect multiple results including glucose, lactose and capillary blood gases
- Some specimens must be transported immediately after collection; transportation should be done at the appropriate temperature depending on the institution and the test
- Specimens for serum or plasma testing should be centrifuged and separated within 2 hours2
- Always ensure specimens are labelled immediately following collection and mixing and before leaving the patient’s side1
- Specimen labels must include the patient’s last and first name, identification number, date and time of collection and collector identifier
EXPERT TIP
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. Rana, S. V. (2012). No Preanalytical Errors in Laboratory Testing: A Beneficial Aspect for Patients. Indian Journal of Clinical Biochemistry, 27(4), 319–321.http://doi.org/10.1007/s12291-012-0271-2
Collection and handling of capillary blood samples
Avoiding pre-analytical errors during collection and handling of capillary blood specimens in blood collection tubes
- Consult institutional guidelines for the volume of sample required for the test type and testing instrumentation
- Ensure each tube is filled to the correct volume of blood as indicated on the collection tube; over-filling or under-filling may lead to inaccurate results1
- Immediately cap specimen tube and mix contents1 by gently inverting several times* to ensure sufficient mixing of blood with tube additive; this additive will promote clotting or prevent clotting as required by the specific test
- Do not shake the tube or mix vigorously as this may cause haemolysis1
- If collecting multiple tubes (following an order of sample collection), cap and mix the sample after each tube is filled
- Correct mixing technique is vital as failure to mix sample with additive sufficiently may lead to specimen rejection and inaccurate test results1
EXPERT TIP
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.
* The exact number of inversions may be determined by the tube manufacturer
Order of sample collection
Order of sample collection
- 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
EXPERT TIP
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.