The general usage method of the dried blood spot collection card is as follows:

Preparation

1. Clean hands: Thoroughly wash your hands with soap and running water to ensure they are clean, avoiding contamination of the collection card and samples. If there is no access to hand – washing facilities, you can also wipe your hands with an alcohol swab. Proceed with the operation after the alcohol has evaporated and dried.
2. Prepare tools: Get ready the dried blood spot collection card, lancet, alcohol swabs, sterile gauze or cotton balls, etc. Ensure that all tools are sterile and within the expiration date.
3. Select the collection site: Generally, the fingertips, such as the two sides of the ring finger tip, are chosen as the blood collection sites. These areas have relatively fewer nerve distributions, less pain, and rich blood circulation, making it easier to collect blood.

Blood Collection Operation

1. Disinfection: Wipe the blood collection site with an alcohol swab, spirally wiping in a clockwise or counter – clockwise direction. The disinfection area should have a diameter of about 5 cm. Wait for the alcohol to evaporate and dry naturally.
2. Blood collection: Use a disposable lancet to quickly pierce the disinfected skin. The piercing depth is generally 2 – 3 mm, just enough to allow blood to flow out smoothly. Avoid excessive squeezing of the blood collection site to prevent excessive tissue fluid from mixing in, which may affect the test results.
3. Collect blood: Let the blood flow out naturally. Bring the blood collection area of the dried blood spot collection card close to the blood drop, allowing the blood to drop naturally onto the designated area of the collection card. Usually, the collected blood is required to form a blood spot with a diameter of about 10 – 15 mm, and the blood spot should be evenly distributed within the collection area. Avoid blood piling up or flowing outside the collection area. Generally, 2 – 3 drops of blood need to be collected to ensure there is enough blood for testing.

Drying and Storage

1. Drying: After blood collection, place the collection card in a clean, well – ventilated place to dry naturally. Avoid direct sunlight and high temperatures. The drying time usually takes 1 – 2 hours. The specific time can be determined according to the instructions of the collection card and the actual situation. Ensure that the blood is completely dry to prevent the components in the blood from deteriorating or degrading.
2. Storage: After the blood is completely dry, put the collection card into the matching sealed bag or storage container and seal it well. Store it under the appropriate temperature and humidity conditions as required by the collection card, generally at room temperature or refrigerated at 4 – 8°C. If long – term storage or transportation is required, special storage measures may be needed, such as adding desiccants, and send it to the testing institution as soon as possible.

Precautions

• Strict aseptic operation: Keep the entire operation aseptic to avoid contaminating the blood sample, which could affect the accuracy of the test results.
• Control the amount of blood collection: The amount of blood collected should be appropriate. Too little blood may prevent the test items from being carried out or lead to inaccurate results, while too much blood may cause the blood to flow, contaminate other areas of the collection card, or waste the sample.
• Avoid hemolysis: During blood collection, avoid excessive squeezing of the finger or subjecting the blood to severe vibration to prevent red blood cell rupture and hemolysis, which may affect the results of some test items.
• Record information: Accurately record the collection time, collector, and the information of the person being collected on the collection card or the storage container for subsequent traceability and testing purposes.

There may be some slight differences in the specific operation of different brands and models of dried blood spot collection cards. When using, it is necessary to operate strictly in accordance with the product instructions.