Question 44

Wipe away the first drop of blood

Wiping away the first drop of blood is essential during newborn screening because it helps to ensure that the specimen collected is free from contamination and contains only interstitial fluid, which can affect test results.

A) Wipe away the first drop of blood

This option is correct because wiping away the first drop of blood prevents the potential contamination of the specimen with tissue fluid. This practice is crucial in ensuring the accuracy of the newborn screening tests, as the first drop can contain impurities that may skew results.

B) Allow the card to dry in a vertical position

This option is incorrect. While it is important for the blood spots to dry properly, allowing the card to dry in a vertical position can lead to pooling of blood and may cause uneven drying, which can affect the quality of the specimen.

C) Smear the blood on the spot collection card

This option is also incorrect. Smearing the blood can lead to an improper sample that may not adequately fill the designated spots on the collection card, potentially compromising the results of the screening tests.

D) Use a capillary tube for collection

This choice is incorrect as well. Using a capillary tube is not the standard method for newborn screening; rather, blood is typically collected directly onto a filter paper card in specific spots to facilitate accurate testing.

Conclusion

Wiping away the first drop of blood is critical for ensuring the integrity and accuracy of the specimen collected for newborn screening. Other options such as allowing the card to dry vertically, smearing the blood, or using a capillary tube either compromise the sample quality or deviate from standard procedures. Therefore, option A is the most appropriate action for phlebotomists during this process.