From the Research
For a 24-hour urine collection to measure protein, the recommended preservative is thymol with isopropanol, as it has been shown to have acceptable effects on urinary measurements, including protein stability, according to the most recent study 1. When considering the preservation of urine samples for protein measurement, it is crucial to prevent bacterial growth and protein degradation, which can occur at room temperature over 24 hours.
- The use of preservatives such as thymol with isopropanol can help maintain sample stability, as demonstrated in the study 1.
- Alternatively, other preservatives like boric acid or hydrochloric acid (HCl) may also be used, but their effectiveness may vary depending on the specific measurement being performed, as shown in studies 2, 3, 4.
- Refrigeration of the sample throughout the collection period can also help maintain stability if no preservative is available.
- It is essential to follow the specific instructions provided by the laboratory, as requirements may vary. The choice of preservative is critical, as some preservatives can interfere with certain measurements, such as urinary citrate, as noted in study 3.
- In contrast, thymol with isopropanol has been shown to be a reliable option for preserving urine samples for protein measurement, making it the recommended choice based on the most recent evidence 1.