What happens to a PCR test sample when it is examined for COVID-19 in UAE?

Abu Dhabi: PCR testing is the gold standard in detecting COVID-19. The acronym stands for Polymerase Chain Reaction, a process that amplifies a sample specific DNA genetic material until it can demonstrate the presence, or absence, of pathogens that may indicate an infectious disease.

The UAE was one of the first countries to roll out widespread COVID-19 screening through PCR tests, and Biogenix Labs in Masdar City, a facility that was built and became operational in just two weeks, were one of the first facilities in the country to offer the tests. The company is part of the network of G42 Healthcare, an Abu Dhabi-based health-tech company that has spearheaded concerted efforts to combat COVID-19 in the UAE. The 4,000-square metre high-throughput lab in Masdar City is also known for being the only facility in Abu Dhabi that offers saliva-based PCR testing for certain categories of the population.

During an exclusive tour, Gulf News was accompanied by Dr Sally Mahmoud, laboratory director and clinical pathologist at Biogenix, through the various stages of testing.

To test for COVID-19, a nasopharyngeal sample is collected from each individual. A sterile swab is inserted on a flexible shaft, which is inserted about two to three centimetres into the nasopharynx area and twirled to collect the sample.

The swab is then placed in a bar-coded sterile tube with a transport medium — a salt solution enhanced with other chemicals to preserve the samples.

The samples are transported to Biogenix Labs in cooler boxes to maintain ideal specimen temperatures of 2 to 8 degrees Celsius, and taken to the sample collection area. Here, they are logged by scanning the bar codes on every sealed tube containing a sample, then segregated based on the type of test to be performed. Some are to undergo regular PCR testing, while others are for rapid PCR testing or genetic sequencing.

After being logged, the samples designated for PCR testing are sent to the extraction area through a pass box, a sterile compartment with glass doors connecting the sample collection area with the extraction area. In the extraction area, lab workers in full personal protective equipment (PPE) extract the samples and place them into tubes. Plates of tubes are then loaded into an automated robotic machine to extract the RNA — the genetic material.

In an adjoining room, reagents are prepared for PCR testing. These are typically enzymes that create DNA strands from the RNA and amplify them, as well as primers and probes, lab-made fragments of DNA that attach themselves to the virus-derived DNA and make them fluorescent so that the original amount of viral genetic material can be detected. Once ready to be mixed in with the samples for PCR testing, these are also sent to the extraction room through a pass box.

Reagents are then mixed with the genetic material to be tested, known as the PCR mixture. After mixing, the new plate is placed into another pass box that connects to the amplification and PCR testing room.

In the PCR testing room, the plates are placed in a thermal cycler, where tubes holding the PCR reaction mixtures can be inserted. The cycler then raises and lowers the temperature of the block in a series of preprogrammed steps to convert the RNA into cDNA and amplify the viral material.

The results of the testing process, whether any COVID-19 genetic material is detected or not, is securely transmitted to computers connected to the thermal cycler, and the lab then communicates this information to the Abu Dhabi Department of Health (DoH), as well as the medical facility that performed the test. Test subjects receive their result via text message, email PDF, or through the Al Hosn app.

At Biogenix, lab safety is necessarily of the utmost importance. A series of steps ensure this safety:

Pass boxes: The use of pass boxes to transfer samples and testing material between the various laboratory sections is absolutely essential, as they ensure that personnel remain safe and that samples are not contaminated or destroyed.

Separated access, PPE: There are separate entrances and exits to the air-purified laboratory, and personnel don full PPE within the various units. In the extraction and sample collection areas specifically, where viral samples are handled, mandatory safety-wear includes N95 masks, eye protection and face shields, in addition to gowns and other PPE. Dedicated laboratory coats are supplied for staff in each area, and gloves are changed between procedures. Lab staff are dedicated to certain functions and change their PPE if they move between departments.

Airlocks: Laboratory rooms are air-locked with negative pressure, preventing any infectious particles from escaping, which ensures an infection-free environment.

Autoclaving: Finally, all samples are autoclaved (sterilised) using high-pressure steam in industrial equipment before being sent for disposal, in compliance with DoH regulations on the standards for disposal of infectious waste.

Supervision: There is a dedicated safety officer and infection control officer to monitor staff compliance, and perform continuous training on safety and infection control procedures.

Standards: At Biogenix Labs, all the steps and measures in the testing process are carried out under strict supervision that ensures local, federal, regional and global standards are followed. Laboratory personnel are trained in all aspects of the testing procedures, and international quality control principles are maintained. Interpretation of test results are fully aligned with the published National Emergency, Crisis and Disasters Management Authority (NCEMA) guidelines for the interpretation of PCR tests.

In support of the PCR testing, Biogenix Labs also provides antibody, antigen serology testing, as well as T-cell response testing services, for patients’ peace of mind. Mandated by the DoH, Biogenix is the only lab to facilitate immunity tests for all vaccinated individuals in the emirate in order to monitor the vaccination outcomes.

In addition, the lab is the official provider of the COVID-19 Proficiency Testing programme, the first of its kind in the region. As part of this role, it verifies the competency of medical laboratories in the UAE carrying out COVID-19 PCR tests, thus raising the standard of quality assurance for COVID-19 testing in the UAE.