What is the purpose of protease testing?

The determination of protease activity can be used to check the content of proteases in the body, which is of great significance for diagnosing some diseases. Protease is a protein with catalytic function, synthesized by the gastrointestinal mucosa, mainly distributed in organs such as blood, gastrointestinal tract, and placenta, with a higher content in the kidneys. In clinical practice, protease activity is mainly measured using enzyme-linked immunosorbent assay, immunofluorescence assay, turbidity assay, etc.
1. Enzyme linked immunosorbent assay (ELISA): It is a method that uses known antibodies to bind to specific antigens and present an immunosorbent effect between known protein antigens. It can be used to check the activity of proteases in the body. This method is simple, fast, and suitable for routine clinical testing;
2. Immunofluorescence method: It is the result obtained by selectively labeling the cell membrane of the test sample with an immunofluorescence probe, using antigen and antibody specific binding reactions, and observing under a fluorescence microscope. This method has high sensitivity and can be used for measuring protease activity, but it requires high requirements and is cumbersome to operate, making it difficult to popularize;
3. Turbidimetric method: The determination of protease activity can be used to check the content of protease in the sample. Through the turbidimetric method, protease inhibitors are added to the sample to be tested and observed under a microscope to determine protease activity. This method is simple, fast, and suitable for routine clinical testing;
4. Electrophoresis method: namely protease electrophoresis, which determines the activity of known proteases through an electrophoresis instrument. Due to the slight enzymatic activity of proteases, this method has high sensitivity and can be used for protease activity determination.
The determination of protease activity can reflect the content of protease in the sample, helping to determine some diseases, such as pediatric macrosomia, cerebral palsy, nephrotic syndrome, etc. In clinical practice, protease inhibitors are usually not used. Therefore, if protease activity needs to be measured, it is recommended to use enzyme-linked immunosorbent assay, immunofluorescence assay, turbidity assay, etc. to avoid measurement errors.