The epidemic in Shanghai has been going on for a long time, and I believe that many people know that Shanghai has also conducted many nucleic acid tests and antigen tests for the whole staff some time ago.

The normal antigen self-test swab is white, then why the antigen swab appeared yellow, is not the quality of the swab factory has been a problem? Here we first look at the antigen swab specific what?

Sponge swab:

The head of the sampler is used polyurethane foam (also known as sponge), from the material properties of raw, due to light (ultraviolet), heat or oxidants will generate coloring azo compounds. The use of certain oxidizing disinfectants (such as chlorine disinfectants) to disinfect them can lead to discoloration of the sampler after oxidation.

Flocked Swabs:

Nylon fibers are used in the head of the sampler. The collected sample remains on the surface of the fiber bundle and is not dispersed and retained in the fibers, making elution easier and also having a better release rate. The resistance to oxidation is stronger than that of sponge swabs.

So that the following are common causes of antigen self-test swab discoloration yellowing:

1, swab outer packaging spray disinfectant or swab contact disinfectant will lead to different degrees of discoloration of the swab head

2, a long time light, exposure to the sun led to swab discoloration

I believe we all know that the yellowing of the swab is not necessarily the manufacturer's quality problems, since this is why antigen self-test swabs also choose easy to discolor the sponge swab?

Flocked swab fibers on the nasal mucosa is more irritating, easy to bleed, so the antigen self-test swab also mostly use a better experience of sponge swabs, while the sampling efficiency of sponge swabs are also more suitable for antigen self-test sample needs.