capillary blood vs. plasma: uses, collection, and alternatives
by Neoteryx, on Apr 3, 2017 6:59:00 AM
Blood plasma is the fluid that conveys the red and white blood cells and platelets through the body. The material, 55 percent of blood volume, is approximately 90 percent water with some proteins, minerals, and other nutrients. Plasma analysis is frequently used to detect the presence of certain viruses, such as HIV.
Plasma must be used immediately, refrigerated, or stored in a frozen state at a temperature below -30°C (-22°F) for up to 36 months. Maintaining a consistent cold chain during storage and transport is an essential requirement for maintaining sample integrity before analysis.
Transporting plasma requires considerable care in special packaging with dry ice or another method of maintaining temperature and careful handling procedures.
Capillary Blood Collection and Storage
Microsampling of capillary blood is an alternative to traditional blood sampling in many cases. Fast and non-invasive, the process requires extracting only a comparatively minute amount of blood, typically with a finger-prick, that can provide much of the information needed to assess an individual's health situation without requiring traditional needle penetration.
The process of extracting capillary blood samples eliminates travel time, storage, and transport costs, providing a more stress-free experience for the patient. In the case of individuals with particularly low blood volume, drawing minute samples can be far less risky.
Also, capillary blood sampling is an appropriate option for donors with fragile or inconspicuous veins, those requiring frequent blood sampling, and in other circumstances in which multiple vein puncturing may be unpleasant or unsafe.
Capillary samples are immediately dried and then placed in a protective envelope devoid of moisture. Dried blood samples (DBS) may then be stored and transported at ambient temperatures.
DBS and Plasma Sampling and Analysis
Dried blood spot sampling is becoming a viable and convenient alternative to plasma sampling in many instances, according to the National Library of Medicine. Its report maintains that microsamples of capillary blood can be used as a convenient alternative for monitoring the progress of antiretroviral treatments for HIV virus, for example.
In further encouraging news, Oxford Academic reports that DBS viral monitoring of antiretroviral therapies for HIV in Tanzania has been very successful. Their assessment confirmed that DBS is a viable alternative for HIV analysis in such resource-deprived locations wherein acquiring, handling, and transporting liquid plasma samples isn't feasible.