ovulation test strips

Specific applications of ovulation test strips:
Predicting the time of ovulation: to help women understand their ovulation cycle so that they can have sex at the best time for conception and improve their chances of conception.
Assisted Reproductive Technology: used to monitor follicular development and determine the time of egg retrieval during assisted reproduction.
Features of ovulation test strips:
Convenience: easy to use and can be self-administered at home.
Sensitivity: able to detect changes in luteinizing hormone (LH) levels at lower concentrations in urine.
Relative accuracy: can reflect ovulation to a certain extent, but the results may have some errors.

The accuracy of ovulation test is relatively high, but not absolutely accurate.
Generally speaking, their accuracy is around 75% to 85%.
However, a number of factors may affect its accuracy, such as the time of the test, urine concentration, individual hormone level differences, and so on.

The detection principle of ovulation test strips is mainly based on the immunochromatographic double antibody sandwich method, which predicts the time of ovulation by detecting the level of luteinizing hormone (LH) in urine, as described below:
Basic Principle
Luteinizing hormone (LH) is normally secreted by the pituitary gland and its level changes during the menstrual cycle. Before ovulation, there is a peak in LH, usually 24-48 hours before ovulation, which then stimulates the ovaries to ovulate.
Ovulation test strips contain solid-phase murine anti-α-LH monoclonal antibody as the detection line and goat anti-mouse IgG polyclonal antibody as the control line, and glass fibers pre-adsorbed with colloidal gold labeled murine anti-β-LH monoclonal antibody and other accessories.
Detection process
When the test strip is immersed in urine, the LH in the urine specimen binds to the β-LH monoclonal antibody colloidal gold pre-solidified at the pad end of the test strip.
This conjugate migrates up the membrane by capillary action and when it reaches the T-zone of the detection line, it reacts specifically with the α-LH antibody on the membrane, resulting in a red band.
Regardless of the presence of LH in the specimen, a red band will always appear in the C zone of the control line as the level continues to migrate, which serves as a control for the validity of the test strip.
Judgment of results
Negative: If the T-zone is lighter in color than the control C-zone, the LH level in the urine is low and has not yet reached its peak, suggesting that ovulation has not occurred.
Positive: When the color of the red band in the T-zone of the test line is closer to or darker than the color of the red band in the C-zone of the control line, it indicates a positive result, which means that the LH level in the subject’s body has risen, and she may be in the period of ovulation, which indicates that she is about to ovulate.