Dotz website states that they use PCR test.In summary, PCR test...

Dotz website states that they use PCR test.
In summary, PCR test is most accurate but require lab and hence long processing time. Antigen test is quick, so more suitable for rapid testing. However, Dotz rapid testing use PCR with 30 minutes turn around time can perform mass testing. The Dotz is really a winner.

the below is from a random website.

While antigen tests look for proteins on the surface of the virus to ascertain the presence of the pathogen, PCR (polymerase chain reaction) tests are engineered to seek genetic material called RNA that instructs the virus to make these proteins. Both tests also require a swab from the back of your nose or throat as a sample and cannot determine whether you are contagious if positive but that’s where the similarities end.In the case of PCR, the sample is sent to a lab where it is heated and cooled using special reagents to convert the virus's RNA into DNA, and then make millions of copies of the DNA, which allows for the identification of the organism. This process can take hours, requires sophisticated lab equipment and technicians, and is typically done one sample at a time, although there are machines that can process multiple samples. Although the sample needs to be sent to a lab, the time consuming process delivers as the results are almost 100% accurate in spotting infected people when there is virus on the swab.In contrast, antigen tests — often referred to as rapid tests — work by mixing the sample with a solution that unleashes specific viral proteins. That combination is then applied to a paper strip that contains a bespoke antibody optimised to bind these proteins if they are present. Like a home pregnancy test the result is reflected as a band on the paper strip.The process doesn’t require a lab, and can be done in up to 30 minutes, but that speed comes at the cost of sensitivity. Although these tests are reliable when an individual has a high viral load, they are far more prone to false-negative results if a person has low amounts of the virus in their body.Sensitivity and specificity are measures of a test’s usefulnessThese two measures are used to determine the credibility of a test: ‘How well does it detect disease, and how well does it detect the absence of disease,’ explained Prof. Deeks.Sensitivity is defined as the proportion of patients with Covid-19 who correctly get a positive result, while specificity is the proportion of patients without an infection that the test correctly identifies as negative.In general, a highly sensitive test has a low false negative rate but runs a risk of false positives if its specificity is not up to scratch. On the other hand, a highly specific test runs a risk of false negatives if the test’s sensitivity is poor, but will generally have a low false positive rate. PCR tests are considered the gold standard because they are generally highly sensitive and highly specific.