As of Dec 27, Xi'an city – capital of Northwest China's Shaanxi province – had reportedly completed four rounds of nucleic acid testing, with about 11.82 million tests conducted on its people.

In a logistics warehouse in the Xi'an International Trade and Logistics Park, or ITL Park, six Yutu air film mobile laboratories are currently lined up in sequence in a row.

Staff members, wearing protective clothing, are going full out to perform nucleic acid testing.

Staff members in one of the Yutu air film mobile laboratories register and verify samples. [Photo/CFP]

After sample addition, extraction, amplification and analysis, test results can be obtained in four to six hours.

The series of laboratories can perform reagent preparations, sample processing and amplification analysis.

These reportedly meet the full requirements for a second-level biosafety laboratory, according to Huang Faping, who is in charge of the labs.

A member of staff performs nucleic acid detection work at the mobile laboratory in Xi'an. [Photo/CFP]

The labs are equipped with nucleic acid extraction and testing equipment independently developed by Xi'an Tianlong Science and Technology Co. They operate 24 hours a day and can complete up to 150,000 sample tests daily.

Using a full negative pressure method for nucleic acid testing, the laboratories strictly undergo disinfection in line with the regulations. After the testing is completed, the laboratories will be removed and the venue will resume its normal use after strict disinfection.

A member of staff uploads nucleic acid test results. [Photo/CFP]