Biological sample processing is a fundamental step in biological experiments, medical testing, and biopharmaceutical research and development. Dispersion, as a core step, directly determines the homogeneity, stability, and accuracy of subsequent experimental results. Its core purpose is to break the inherent aggregated state of biological samples, dispersing tissues, cells, or microorganisms into individual units or homogeneous suspensions, eliminating interference from sample heterogeneity, and laying the foundation for subsequent extraction, detection, and culturing operations.
The selection of biological sample dispersion techniques needs to consider factors such as sample type, subsequent experimental requirements, and dispersion efficiency. Currently, commonly used methods are mainly divided into three categories: mechanical dispersion, enzymatic dispersion, and chemical dispersion. Each method has its advantages and is suitable for different application scenarios. Mechanical dispersion, due to its simplicity, speed, and efficiency, has become the most commonly used basic method in laboratories. It mainly breaks up sample aggregates through physical shear force, including grinding, shearing, centrifugation, and filtration.
For soft tissue samples with low fibrous content, initial dispersion can be achieved by cutting them into small pieces with sterile scissors and repeatedly pipetting them. For more resilient or dense tissues, a grinding tool with buffer solution can be used, followed by filtration through a sieve to remove impurities and obtain a homogeneous cell suspension. While mechanical dispersion is convenient, the force and time must be carefully controlled to avoid excessive shearing that could lead to cell rupture and loss of bioactive substances.
Enzymatic dispersion is a precise dispersion method for samples rich in connective tissue or with tightly connected intercellular structures. It utilizes specific enzymes to degrade the intercellular matrix and adhesion substances, achieving sample dispersion under gentle conditions while maximizing the preservation of cell viability and the integrity of biomolecules. Commonly used enzymes include collagenase and trypsin. Collagenase specifically hydrolyzes collagen, making it suitable for dispersing fibrotic tissues; trypsin cleaves intercellular adhesion proteins, making it suitable for dispersing soft tissues and cultured cells.
Chemical dispersion utilizes chemical reagents to disrupt the ion bonds between cells, weakening cell adhesion. Chelating agents are commonly used, binding to metal ions necessary for cell adhesion and gently separating sensitive cell types. This method is often used in conjunction with enzymatic dispersion to enhance the dispersion effect. Regardless of the method used, strict aseptic technique must be followed during dispersion, controlling conditions such as temperature and pH to avoid sample contamination and degradation of bioactive substances.
Biological sample dispersion techniques are widely used in cell biology, medical testing, and biomedicine. In experiments such as single-cell sequencing, tumor cell detection, and microbial analysis, high-quality dispersion can improve detection sensitivity and experimental repeatability. In the extraction of bioactive substances, uniform dispersion increases the contact area between the sample and the extraction reagent, improving extraction efficiency.
With the continuous development of experimental techniques, dispersion technology is upgrading towards precision, gentleness, and efficiency. By optimizing dispersion parameters and combining multiple methods, sample dispersion quality can be further improved, providing more reliable technical support for biomedical research and clinical applications. The rational selection and standardized use of dispersion techniques are crucial for ensuring the quality of biological sample processing and facilitating the smooth conduct of experimental research.
