Biological sectioning is a very important technique in biological experiments, which can cut biological samples into thin sections for easy observation and research. The biological sectioning process is the basis for students to learn biological experiments, so let's introduce the steps and precautions of the biological sectioning process.
1. Prepare experimental materials and tools Before conducting a biological slice test, you must first prepare the materials and tools required for the experiment. It mainly includes biological samples (such as animal tissues or plant tissues), slicing knives, glass blades, microscope slides, microscope coverslips, microscopes and microscope lens cleaning papers, etc.
2. Preparation of biological samples Selecting the right biological sample is a prerequisite for biosectioning. Samples should be fresh, intact, and representative of tissues or cells, and samples should be protected from damage or denaturation as much as possible.
3. Fixation In order to maintain the morphological structure of the sample and the chromosome morphology of the cell, it is necessary to fix the biological sample. Commonly used fixatives are acetaldehyde and acetic acid. The choice of fixative depends on the purpose of the experiment and the characteristics of the sample.
4. Dehydration treatment The fixed biological sample contains a large amount of water, which needs to be gradually replaced with an organic solvent, such as ethanol, through dehydration. The purpose of dehydration is to allow the water in the cells or tissues to be gradually replaced by organic solvents for subsequent penetration and embedding.
5. Embedding treatment The dehydrated biological sample needs to be embedded, that is, the sample is immersed in molten wax or resin to fix it in a certain position. The choice of embedding material should be determined according to the needs of the experiment and the characteristics of the sample.
6. Sectioning The embedding of biological samples needs to be cut into thin slices using a slicing knife or glass blade. The thickness of the section is generally 5-10 microns, and the internal structure of cells and tissues can be observed with a microscope.
7. Staining After the section is completed, in order to observe and study the structure of cells and tissues more clearly, the section needs to be stained. Commonly used dyeing methods include hematoxylin-eosin staining, bromophenol blue staining and fluorescent staining.
8. Cover After the staining is completed, the section needs to be fixed on the microscope slide and the coverslip should be added. The purpose of the cover is to protect the slice from deformation or damage.
9. Observation and Analysis After the mounting is completed, the cells and tissue structures in the sections can be observed and analyzed using a microscope. It is important to note that the focal length and light source of the microscope should be adjusted when observing to obtain a clear image.
The biosectioning process is an experimental technique that requires care and patience, and each step needs to be strictly controlled and operated. When conducting experiments, it is necessary to pay attention to personal safety and avoid contact with hazardous substances and sharp tools. By learning and practicing the biological sectioning process, we can better understand the structure and function of organisms, and provide strong support for the research and application of biology. It is hoped that students can master the technical points of biological slicing in the learning process, and improve the ability of experimental operation and the accuracy of experimental results.