Dried Blood Spot Collection Cards: A Novel Way to Collect Blood Samples

Blood tests have a wide range of applications in healthcare. From detecting various diseases to spotting early symptoms, a blood test can have life-saving benefits. Blood sample collection and storage methods have evolved with time. The practices may vary based on the availability of technology and equipment.

Ideally, the blood sample should be collected based on the requirements of the tests. With the volume of blood samples withdrawn from a person’s body, at least two separate or duplicate blood tests should be possible. The storage of blood samples should be done under refrigeration at a temperature of 4 to 8 degrees Celsius.

However, conventional blood sampling, storage, and shipment are not always viable options at every healthcare institution. The lack of availability of equipment such as refrigerators can put limitations on the storage and stabilization of blood samples for a longer duration. In such a scenario, the use of dried blood spot collection cards enables more storage and transport flexibility and simplicity.

How Dried Blood Spot Collection Cards Work?

Originated in the 1980s, the dried blood spot (DBS) testing method is widely used for newborn screening (NBS) to evaluate the presence of any genetically inherited or congenital disorders. The collection of blood samples in DBS is performed without venipuncture, where a needle and tube are used for the sampling of blood.

In DBS testing, capillary blood samples are collected by making a fingerstick or fingerprick at the end of a finger and allowing blood to drop onto filter paper also known as DBS cards. These blood spots then dried on the cards completely before their shipment for further clinical testing procedures. 

The dried blood samples can be kept with a dehumidifier at room temperature for up to two weeks. The DBS cards can also be used for detecting the presence of IgM and IgG antibodies that fight against viruses such as HIV, HCV, and HBV, among others. Healthcare professionals over the last two decades have started utilizing DBS cards for testing different infectious diseases. 

Human immunodeficiency virus (HIV) is one of the major infectious diseases for which the utilization of DBS cards has significant scope. The majority of DBS tests are proven to be accurate. According to research, 99 out of 100 HIV infection cases detected using the DBS test method are likely to be accurate.

Major Types of DBS Collection Cards

Some of the major types of DBS cards available in the market are Whatman 903, Ahlstrom 226, FTA, and Munktell TFN, among others.

Whatman 903: Also known as Whatman 903 protein saver cards. There are two versions of the W-903 card available in the market, one includes five circles and another has four circles. The spots are up to 5 inches sample spots. Each spot can hold up to 70 – 80 µl (microlitre) of blood. These cards have wraparound covers to protect paper and blood samples before and after the collection process.

Ahlstrom 226: It is made of 100 percent pure cotton linter filter paper. The device is validated for the uniform distribution of blood samples, which facilitates improved reliability of tests across the dried sample spots. This medical device card is free of chemicals owing to which tests can be considered safe and pure. Desiccation (moisture removal) is not required most of the time. The collected blood sample is allowed to dry completely before further shipment or analysis process.

Advantages of DBS Cards

The dried blood spot collection can enable the home-based diagnostics process. A person can self-collect and ship blood samples with the DBS cards to diagnostics centers. The growing home healthcare is supporting the collection of patient biomarkers such as swabs, saliva, and blood sample from home. Thus, propelling demand for DBS cards.

The DBS collection is a minimally-invasive sampling method, as it is not necessary to take blood samples through the venous collection method. A small prick on a finger or with a heel puncture (in newborns) can provide sufficient drops of blood for testing. This makes it the most suitable method for neonates (newborns) and children. The 4 to 5 spots of dried blood can be utilized for carrying out different tests, and do not require collecting blood samples repeatedly. 

Cost-effectiveness is another major advantage facilitated by the DBS testing method. The cards allow blood sample safe storage for days with minimum measures for maintaining temperatures. The conventional blood sampling method requires refrigeration equipment, special shipment arrangements, and other such methods. 

The blood sample collection and storage needs to be carried out with expert involvement, whereas, the DBS cards allow more flexibility in terms of blood collection and shipment of the samples. The remote areas where only primary care is available, the DBS cards enable ease of storage and shipment. This is a suitable solution for saving healthcare costs for low to middle-income generating parts of the world.

Major Dried Blood Spot Collection Cards Providers

Some of the prominent providers of dried blood spot cards in the global healthcare industry are Ahlstrom; PerkinElmer Inc.; QIAGEN; CENTOGENE N.V.; F. Hoffmann-La Roche Ltd; Pall Corporation.; Shimadzu Scientific Instruments.; Eastern Business Forms, Inc; ARCHIMED Life Science GmbH; and Hemaxis. These companies with research and development are launching highly safe, flexible, and pure DBS cards to enable healthcare professionals to derive maximum use of blood samples while reducing healthcare costs significantly.

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