Pregnancy test kit ~ The working principle

How does pregnancy test kit works?

In early days, women used to urinate in wheat seeds to check whether they conceive or not. When the seeds start to sprout, it confirms their pregnancy. This is because oestrogen contained in their urine responsible for the seed sprout. In 1963, a research conducted to check the accuracy of pregnancy and invented the kit which gives 70% of accuracy but it can't tell the sex. Let's see how it works.

      The mechanism behind these is binding the HCG hormones. HCG stands for Human Chlorionic Gonadotropin which is a hormone supports the formation of placenta. It transfers the nutrients from the mother to fetus. The hormone is secreted in the initial level of pregnancy and the pregnancy test involves in detecting these hormones. The urine is collected and dropped in the fiber. After that it travels through three seperate zones, each carries an important task.

                                                        The three zones are the reaction zone, the test zone and the control zone.

Reaction zone:

When the urine passes through this zone, there is Y Shaped antibodies which involves binding of the HCG hormone present in the urine. The Y shaped antibodies contain handy enzymes which has the ability to turn dye molecules. Then the urine picks up all the AB1 enzymes and travels to the test zone.

Test zone:

This zone also contain more Y shaped antibodies that will also stick to the HCG. As it looks like a sandwhich by binding HCG by Y shaped antibodies(AB1 & AB2) on both sides,it's called sandwhich assay. It sticks to the test zone allowing dye activating enzymes to do it's job and creates a visible pattern. If there is no HCG, the wave of urine just passes on. 

Control zone:

This zone confirms whether the test is worked properly. The unbounded AB1 enzymes in the previous zones are ended here and releasing more dye and make a visible pattern appear. If the visible pattern doesn't appears, it indicates that the test ends faulty.

                             There are several qualitative and quantitative tests available for the identification of pregnancy and it is one among them. It may be advised to go to doctor and check pregnancy for the better identifications and safe results.