A phlebotomist is performing a venipuncture on a patient who is allergic to alcohol. Which of the following is an appropriate antiseptic to use in place of alcohol?

Choice A Reason:
The age of the newborn is important for certain metabolic screenings, as some metabolites may not be present or at measurable levels immediately after birth. However, the requirement for the newborn to be at least 3 days old is not a standard for all blood spot collections for inborn errors of metabolism (IEM). Some screenings are performed within 24 to 48 hours after birth.

Choice B Reason:
While it is important that the circles on the filter paper are adequately filled to ensure there is enough blood for the test, the requirement for them to be at least half filled is not specified in the guidelines. The focus is usually on ensuring the blood spot is of the right size and properly saturated through the filter paper.

Choice C Reason:
The inclusion of the first drop of blood is not typically a requirement. In fact, the first drop is often wiped away to avoid contamination with tissue fluids that could affect the test results. Subsequent drops are used to fill the circles on the filter paper.

Choice D Reason:
The specimen must be completely dried before the test can be processed to prevent degradation or hemolysis of the blood sample. This is a critical step in the preparation of the sample for accurate testing of IEM. The drying process helps preserve the integrity of the metabolites to be analyzed.

Choice A Reason:
SST, or Serum Separator Tube, contains a gel at the bottom to separate the blood from the serum upon centrifugation. It does not indicate plasma; rather, it is used to collect serum after the blood has clotted. The SST allows for the blood to clot and the serum to be separated for various tests that require serum instead of plasma.

Choice B Reason:
Sodium fluoride is a common additive in collection tubes that serves as a glycolysis inhibitor. It preserves glucose levels and is not specifically indicative of serum. However, it is often used in grey-top tubes, which are typically used for glucose testing and may contain plasma, not serum.

Choice C Reason:
Sodium citrate is an anticoagulant that binds calcium in the blood, preventing clotting. Tubes with sodium citrate are used to collect plasma for coagulation studies, not serum. Therefore, this statement is incorrect as sodium citrate indicates plasma, not serum.

Choice D Reason:
EDTA, or Ethylenediaminetetraacetic acid, is an anticoagulant that binds calcium ions, preventing blood from clotting. Tubes with EDTA are used for collecting plasma because they prevent clotting and allow for the separation of plasma from the blood cells upon centrifugation. This is the correct choice as EDTA indicates plasma.