Plasma-Free RNA Preservation Tubes are vacuum blood collection tubes specifically designed for the collection, stable preservation, and transport of cell-free nucleic acids (such as cell-free RNA) in blood samples. Their core function is to prevent the rupture of blood cells and the release of endogenous RNA, thereby maintaining the integrity of plasma-free RNA for subsequent molecular biological analysis.

‌    These tubes achieve stabilisation through integrated preservatives, anticoagulants, and RNase inhibitors.‌ Preservatives rapidly fix nucleated blood cell structures, preventing RNA leakage from cellular rupture; anticoagulants (such as K3EDTA) inhibit blood coagulation; while RNase inhibitors suppress nucleases to prevent RNA degradation. ‌34 This design permits stable sample storage at room temperature (18–25°C) for 5–7 days, or up to two weeks at 4°C, significantly streamlining sample handling procedures.‌

‌    Plasma Free RNA Preservation Tubes are widely employed in clinical research, drug development, and diagnostic analysis, such as liquid biopsy for early cancer screening or disease monitoring. Post-collection samples can be directly processed using commercial kits for RNA extraction, with downstream applications including quantitative RT-PCR, transcriptome sequencing, and gene expression analysis.‌ Free RNA preservation tubes are specifically designed to store free RNA samples, preventing contamination and degradation. They ensure the accuracy of liquid biopsies and play a vital role in precision medicine. Their specific functions and applications are analysed below:

Functions of Free RNA Preservation Tubes:

1. Stabilising blood cells and preventing coagulation: These tubes stabilise blood cells and inhibit blood clotting, thereby preserving free RNA (cfRNA) in plasma at room temperature. This property eliminates the need for immediate complex pre-processing after collection, simplifying workflows and facilitating subsequent experiments.

2. Inhibition of nucleases to prevent RNA degradation: Blood contains various nucleases that degrade RNA, compromising sample quality. Free RNA preservation tubes effectively suppress these nuclease activities, preventing RNA degradation and ensuring sample integrity and viability.

3. Excellent sealing performance: Free RNA preservation tubes possess superior sealing properties, preventing external contaminants from entering the sample. This property is crucial for safeguarding samples from microbial or chemical contamination, thereby enhancing the accuracy and reliability of subsequent experiments.

4. Stable transport/storage at ambient temperature: Free RNA preservation tubes maintain stability during transport and storage at room temperature for over five days, meeting requirements for long-distance sample transfer and extended preservation. This feature allows greater flexibility in sample collection and transport, reducing reliance on cold chain logistics and lowering associated costs.

Applications of Free RNA Preservation Tubes:

1. Tumour Gene Detection: In tumour gene detection, Free RNA Preservation Tubes protect RNA within samples from degradation and contamination, ensuring accurate test results. By detecting free RNA in tumour patients' blood, the presence of tumours can be promptly identified, their type and stage determined, providing crucial evidence for clinical treatment.

2. RNA Expression Analysis: Free RNA preservation tubes facilitate RNA expression analysis by preserving sample RNA. This enables researchers to conduct multiple tests on the same sample at different time points, allowing for more precise analysis of gene expression trends. This is crucial for studying gene function and disease mechanisms.

3. Immune Expression Studies: Free RNA preservation tubes also play a vital role in immune expression research. By preserving RNA within samples, researchers can investigate gene expression alterations in immune cells under varying conditions, elucidating the molecular mechanisms of immune responses and identifying novel targets and strategies for immunotherapy.