Dried blood spot collection offers a simple solution for collecting, preserving, and transporting blood samples. At-home testing using dried blood spot collection eliminates the need for venipuncture blood draw in a lab and allows convenience by taking your sample from the comfort of your own home.
Often, we see questions about the reliability or accuracy of these tests.
Dried blood spot testing has been around for decades.
In 1913, physician Ivar Bang introduced the idea of using dried blood as a sampling method. The idea was actualized in 1963 by microbiologist Robert Guthrie. Guthrie initially wanted to screen intellectually disabled children using this approach, which gave way to the introduction of newborn screening for inherited metabolic disorders.
The limitations of sensitivity and specificity when screening such small sample volumes of blood restricted the use of dried blood spots for many years. As mass spectrometry (an analytical technique that measures the mass-to-charge ratio of ions) expanded into clinical laboratories, the applications of blood spot collection grew, too.
Today, this method tests hundreds of biological markers successfully.
Draw dried blood spot samples using a finger-prick via a small lancet. A few droplets of blood are then dropped drop onto specially manufactured absorbent filter paper.
The Clinical and Laboratory Standards Institute recommends the use of two specific collection cards: the Whatman 903 and Ahlstrom 226. These two collection cards are both approved by the Food and Drug Administration, Newborn Screening Quality Assurance Program, and the Centers for Disease Control and Prevention.
The blood is allowed to saturate the paper thoroughly and air-dries for at least 30 minutes. Once dry, these cards are stable for shipment and storage.
While samples do not need to be specifically temperature regulated, it’s advisable to store the collection card in a cool place and ship to the laboratory as soon as possible.
It's good to note that reference ranges vary by lab, meaning that different labs may yield different results. That is normal. Variability can occur due to differences in testing equipment, chemicals used, and analysis techniques. This variability is the reason you should use the range supplied by the lab that analyzed your test to evaluate whether your results are within normal limits. We recommend you use the same laboratory each time you have your labs drawn.
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