Trizol RNA Extraction for Animal Experiments: A Basic Guide Even Beginners Can Understand

What is Trizol, and why is it commonly used in animal experiments?

In animal experiments, researchers often need to extract RNA from tissues such as the heart, liver, spleen, lung, kidney, or muscle to observe changes in gene expression. Trizol is a commonly used total RNA extraction reagent, and its main components include phenol, guanidine isothiocyanate, and others. Its function can be understood as "first disrupting cells, then separating RNA from other components." Phenol can denature proteins, and guanidine isothiocyanate can inhibit RNase activity, thereby protecting RNA from rapid degradation. Many laboratories choose Trizol because it has good adaptability to a variety of animal tissues, and its operating procedure is relatively well established.

From animal tissue to RNA: breaking down the key steps

Generally speaking, using Trizol to extract RNA from animal tissues involves several main steps. The first is sampling and preservation: after animal tissue is removed, it should be processed as soon as possible; if it cannot be extracted immediately, it can be snap-frozen in liquid nitrogen or stored in a dedicated RNA preservation solution. The second is lysis: place an appropriate amount of tissue into Trizol and homogenize thoroughly. The amount of tissue should not be too large, otherwise lysis will be incomplete; a common recommendation is several tens of milligrams of tissue per milliliter of Trizol. After homogenization, add chloroform, mix, and centrifuge; the liquid will separate into an aqueous phase, an interphase, and an organic phase, with RNA mainly in the aqueous phase. Carefully aspirate the aqueous phase, then add isopropanol to precipitate RNA, wash with ethanol, and finally dissolve in RNase-free water. The entire process needs to avoid contamination with exogenous RNases.

Protection and storage in routine operations

Trizol contains components such as phenol and is somewhat corrosive and irritating. During operation, it should be handled in a fume hood, and gloves, goggles, and a lab coat should be worn. If skin or eyes come into contact with it, immediately rinse with plenty of water and handle it according to laboratory safety procedures. After the reagent is opened, it should be stored protected from light and at low temperature, and its appearance should be checked before use to confirm it is normal. Waste liquid containing Trizol must not be poured directly down the drain; it should be collected separately and handed over to a qualified unit for disposal.

How to determine whether extraction was successful

After extraction is completed, concentration and purity can be measured with a UV spectrophotometer. Generally, attention is paid to the A260/A280 ratio; the ratio for pure RNA is often around 1.8 to 2.0. A low A260/A230 ratio may indicate residual salt or phenol. More importantly, RNA integrity should be observed by agarose gel electrophoresis, where clear 28S and 18S bands can usually be seen. Beginners can first practice with tissues that are easier to extract, such as liver, to gradually become familiar with the pace of the procedure. Once RNA quality is stable, proceed to the next experiment, and the results will be more meaningful as a reference.