Product Introduction:
Once a biological sample is collected, its RNA begins to become quite unstable. Rapid stabilization of RNA and maintenance of RNA expression levels are the primary conditions for obtaining accurate gene expression analysis data. In addition, it is necessary to prevent the activation of gene expression elevation or downregulation caused by sample processing. Sample RNA protectant is a liquid non-toxic animal tissue preservation reagent. It can quickly penetrate into tissue cells and protect non frozen cell RNA from degradation by efficiently inhibiting RNase activity, making it easier to process and freeze tissue samples in liquid nitrogen after obtaining them, and facilitating subsequent experimental operations. The use of tissue RNA protective solution eliminates the inconvenience of using liquid nitrogen or ultra-low temperature refrigerators. Moreover, storing different batches of tissue specimens in this protective solution can immediately terminate and fix the temporal changes in RNA expression, reducing experimental group errors. Sample RNA protective agents can be widely used in various vertebrate samples, including brain, heart, kidney, spleen, liver, and lung. After immersing fresh non frozen tissue in sample RNA protectant at a ratio of 1:10, the sample can be stored at 37 °C for 1 day, room temperature for 1 week, and 4 °C for 1 month; After soaking at 4 °C, the tissue can be stored for a long time at -20 °C or -80 °C.
Precautions：
1. Sample RNA protectants may precipitate or crystallize, and should be completely dissolved at room temperature or 37 ° C before use.
2. Sample RNA protectants are only suitable for fresh animal tissues and cannot be used for frozen tissues.
3. The size of the tissue block should not exceed 0.5cm on any side. If the tissue is too large, it can be cut into pieces and then soaked in 10 times the volume of sample RNA protectant.
If the tissue stored in the sample RNA protectant needs to be transported over long distances, it is necessary to ensure that the tissue is completely immersed in the sample RNA protectant during transportation.
5. For your own safety, please take protective measures such as wearing lab coats and gloves before using the reagents.
Instructions for Use：
1 Animal organization
1.1 Before cutting the tissue, estimate the volume (or weight) of the tissue to be used. Take out the sample RNA protectant at a ratio of 1:10 (tissue: sample RNA protectant) for use (for example, if the tissue volume is 100mg, 1mL of sample RNA protectant is required. Proportional reduction has no effect on the experimental results, and proportional enlargement requires cutting the tissue. If the tissue sample is too large, tissue blocks with a side length less than 0.5cmx0.5cmx0.5cm should be cut before storage. When storing, it should be noted that the tissue block must be completely immersed in the protective solution. Note: The amount of sample RNA protectant should be at least 10 times the volume (or weight) of the tissue.
1.2 Long term storage can be placed at -80 ° C: Incubate the sample with sample RNA protectant overnight at 2-8 ° C, then remove the sample and store it at -80 ° C. For cultured cells, the sample RNA protectant containing cells can be directly frozen. When using the sample, melt it at room temperature.
1.3 Long term storage can also be placed at -20 ° C: Incubate the sample with sample RNA protectant overnight at 2-8 ° C, and then transfer to -20 ° C. Samples soaked in RNA protectants may not freeze at -20 ° C. Low temperature storage will cause crystallization or precipitation of the solution, which will not affect the protective effect of RNA and subsequent purification of RNA. If you are concerned that crystallization may affect subsequent experiments, you can remove the sample before freezing and then freeze it.
1.4 Short term storage at 2-8 ° C: Incubate the sample with sample RNA protectant at 2-8 ° C and store for one month.
2 Plant tissues
Plant tissue can be soaked in 10 times the volume of sample RNA protectant. Due to the complexity of plant tissue, it may not be suitable for all tissues. Plant tissues have natural barriers that prevent diffusion, such as the wax on the surface of leaves, which needs to be broken down to allow the sample RNA protectant to penetrate into the tissue. Any method of breaking wax can be used, such as cutting or physical tearing. See the storage method above.
3. Cultivate cells
Use laboratory standard procedures to precipitate cells. Wash with PBS to remove the culture medium. Resuspend cells with a small amount of PBS and add 10 times the volume of sample RNA protectant. See the storage method above.
4 white blood cells
After isolating white blood cells from whole blood, adding sample RNA protectant according to the method of "culturing cells" can preserve white blood cells. White blood cells that have not been isolated from whole blood cannot be preserved with sample RNA protectant because they contain high concentrations of protein, which will form a precipitate after adding sample RNA protectant. Storage methods are described above.
5 bacteria
Adding sample RNA protectant according to the method of "cultivating cells" can preserve RNA in Escherichia coli. The storage method is shown above.
6 Subsequent RNA isolation experiments
6.1 For tissue samples, sterile forceps can be used to remove the sample from the sample RNA protectant and soak it in the RNA separation lysis buffer. For organizations, rapid homogenization is necessary.
Attention: Storing the tissue in a sample RNA protectant will make it harder and more difficult to homogenize compared to fresh tissue. Using a dissecting knife to cut tissue into small pieces will make homogenization easier.
6.2 For cell samples, centrifugation can be used to collect cells and remove sample RNA protectants; RNA can also be extracted directly from the mixture. Due to the higher density of sample RNA protectants compared to cell culture media, cells cannot be precipitated under conventional centrifugal force. For example, for HeLa cells, 3000g can induce cell precipitation.
6.3 If a one-step method is used to extract RNA, such as using Trizol, the aqueous phase may become blurry during the extraction process, resembling a cloud like state, which does not affect the quality of RNA. RNA extraction can continue according to Trizol's instructions.
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