The detection principle of the ovulation test strip mainly involves predicting ovulation by detecting the change in the level of luteinizing hormone (LH) in urine. The following is a detailed introduction:

2025/02/26Class Product news ovulation test strip ovulation test strip00

The Relationship between LH and Ovulation: During a woman’s menstrual cycle, the ovaries undergo a series of changes, in which LH plays a crucial role. Before ovulation, the LH level in a woman’s body rises rapidly, forming an LH peak, which usually occurs about 24 to 48 hours before ovulation. The LH peak stimulates the maturation of the follicles in the ovary and eventually leads to ovulation. Therefore, by detecting the LH level in urine, the time of ovulation can be roughly determined.
The Detection Mechanism of the Test Strip: The ovulation test strip adopts the principle of immunochromatographic double-antibody sandwich method. The test strip contains antibodies fixed at specific positions, and these antibodies can specifically bind to LH. When the LH in the urine binds to the antibodies on the test strip, an antigen-antibody complex is formed. Subsequently, the complex will move along the test strip and bind again to another antibody labeled with a specific substance (such as colloidal gold) on the test strip, thus forming a visible colored band on the test strip. If the LH concentration in the urine is low, the color of the band is light; when the LH concentration reaches a certain level, that is, close to or reaching the peak value before ovulation, the color of the band will deepen, becoming similar to or darker than that of the control line, indicating that ovulation is about to occur.
The Chemical Basis of the Color Reaction: Taking the common ovulation test strip using the colloidal gold method as an example, when LH binds to the antibody labeled with colloidal gold, the colloidal gold particles will aggregate. This aggregation will change the scattering and absorption characteristics of the colloidal gold particles to light, causing the test strip to show different colors. When there is no LH or the LH concentration is very low, the colloidal gold particles are dispersed, and the test strip shows a lighter color; when the LH concentration increases and a large number of colloidal gold particles aggregate, the color of the test strip will deepen. Through the change in color, the change in the LH concentration is reflected, and then it is determined whether ovulation is about to occur.