American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

In what condition must the blood for plasma renin activity testing be transported?

1. At room temperature

2. In ice water

3. In a heated container

4. Wrapped in a warm towel

The correct answer is: In ice water

For plasma renin activity testing, the blood must be transported in ice water to maintain the stability of the renin enzyme. Renin is a sensitive enzyme that can degrade if exposed to elevated temperatures or prolonged periods outside optimal conditions. Ice water slows down metabolic processes and helps preserve the blood sample, ensuring accurate measurement of renin levels. Maintaining correct transport conditions is crucial for accurate laboratory results, especially for substances like renin that can be affected by temperature fluctuations. Additionally, while other options may suggest different forms of temperature control, none effectively achieve the necessity of keeping the sample at a low temperature to prevent the degradation of renin.