83. A phlebotomist should identify that a blood spot collection for inborn errors of metabolism requires which of the following?
Answer: D
The specimen must be completely dried before the test can be processed.
For blood spot collection in the context of inborn errors of metabolism, it is essential that the specimen is allowed to dry completely prior to processing. This ensures the integrity of the sample and accurate test results.
A) The newborn must be at least 3 days old.
This option is incorrect because while timing is important for certain metabolic tests, the requirement for drying the specimen takes precedence in the context of sample handling. The age of the newborn primarily affects the timing of when the test can be performed, not the preparation of the sample.
B) The circles on the filter paper must be at least half filled.
This option is also incorrect. Although it is important for the sample to adequately saturate the filter paper, the critical aspect of handling the sample is ensuring that it is completely dried before processing. The filling of the circles does not directly correlate with the accuracy of the test results as much as the drying process does.
C) The first drop of blood immediately following the puncture must be included.
This statement is incorrect. The inclusion of the first drop of blood is not necessary for blood spot collection for metabolic testing. In fact, it is commonly advised to discard the first drop to avoid contamination, further emphasizing that drying the specimen is paramount for testing accuracy.
D) The specimen must be completely dried before the test can be processed.
This is the correct option. Allowing the blood spot to dry completely is crucial for the stability of the sample and ensures that the results of the metabolic tests are reliable. Proper drying prevents degradation of the sample components.
Conclusion
The requirement for the specimen to be completely dried before processing is critical to ensuring accurate results in tests for inborn errors of metabolism. Other options either misinterpret the requirements for blood collection or do not address the importance of sample preservation. Therefore, option D is not only the correct answer but also highlights a fundamental aspect of laboratory protocol in phlebotomy.