What is Dried Blood Spot Sampling?
Dried blood spot (DBS) analysis has been known for more than five decades. It is an easy way of collecting, shipping and storing blood samples. In recent years the usage of DBS has gained increasing importance since this method shows strong advantages compared to the conventional collection and analysis of blood or plasma samples. These advantages include the need for remarkably lower blood volumes and easier shipping and storage, mainly at ambient temperatures. This leads to a simplification of the blood collection process and a significant reduction in the costs involved.
The blood sample needs to be extracted from the DBS card prior to the analysis. This was a major drawback of DBS since sample extraction from a high number of DBS cards was very tedious and required many process steps to be performed manually. Hence, analysis of DBS was time-consuming and costly before the introduction of the CAMAG DBS-MS 500. The DBS-MS 500 enables fully automated sample recognition, integration of an internal standard to the DBS and direct sample extraction of the DBS from the card. The extract is guided online to an analytical system of choice (i.e. MS, LC-MS), and the system is cleaned after each extraction.
A typical field of application is newborn screening (NBS), where only a very small amount of blood from the newborn is available. Every newborn in developed countries is screened for inborn disorders via DBS. Also, therapeutic drug monitoring (TDM) is a major field of interest for the DBS technology, since drawing blood samples can be performed by the patients themselves and it is minimally invasive. Samples can be shipped to centralized laboratories for analysis via the standard mail delivery. Furthermore, in preclinical studies, the number of test animals can be reduced (due to the need for lower blood volumes), which is in accordance with the 3R requirement of animal studies (replacement, reduction, refinement). For similar reasons, DBS is also applied in clinical studies. Personalized healthcare analysis of metabolites via automated DBS analysis is more affordable for the end-user and represents a growing market. Testing of possible abuse of regulated substances is performed via DBS as well.
Other body fluids
Dried Urine Spot
Urine is a biological fluid that is readily collectable and available. The shipment of urine samples is inconvenient. The sample preparation is tedious and requires many consumables. Dried Urine Spot (DUS) cards can easily be shipped and are integrated into the fully automated analysis concept for the DBS-MS 500. The urine matrix has been extensively researched and tested, and the technology has been in place for years. Quantification of targets in DUS can be facilitated by using creatinine as a marker for the urine concentration [1]. Specific metabolites present in urine reflect a previous drug uptake for a period of hours to a few days.
Dried Plasma Spot
Dried Plasma Spot (DPS) analysis is the combination of well-known and established analytical methods with the general advantages of dried matrix spot analysis, such as easy shipping and storage, increased sample stability and fully automated sample handling. Plasma of different patients has no significant difference in viscosity in contrast to whole blood samples. It can also be directly extracted from the filter paper card and then be guided online into the analytical system.
[1] M. Luginbühl, W. Weinmann, and A. Al-Ahmad, “Introduction of sample tubes with sodium azide as a preservative for ethyl glucuronide in urine,” Int. J. Legal Med., vol. 131, no. 5, pp. 1283–1289, 2017.