CORONAVIRUS TESTING LAB

In Estonia, the majority of coronavirus SARS-CoV-2 RNA analyses are handled in the SYNLAB Eesti molecular biology laboratory located in the Veerenni Health Centre, where nasopharynx samples arrive from all over Estonia. The samples are mainly transported by SYNLAB logistics experts, but sometimes healthcare professionals transport them separately, using cargo or taxi services, if necessary. The total number of people working at the SYNLAB Eesti laboratories and blood collection points is about 400 people; of them, nearly 40 specialists have received special training and have been involved in coronavirus testing in the molecular biology laboratory 24/7 since this past spring. The samples are analysed and results are issued within approximately 24-48 hours. How is this made possible?

SAMPLES IN PRE-ANALYSIS

The samples arriving at the laboratory are first taken to the pre-analysis department where the samples that have been packed in line with WHO regulations are unpacked. It is then verified that the sample material is correctly labelled, a respective order has been placed, the nasopharyngeal swab is collected in the correct specimen receptacle, etc. The department has about 30 staff members who handle the coronavirus materials, as well as other samples arriving at the laboratory on a daily basis.

 EXTRACTING RNA FROM THE SAMPLE

From the pre-analysis department, the samples are transported on a specific tray using the laboratory elevator onto a lower floor where the molecular biology department is located. Within the molecular biology department, in the microbiology lab with risk level 2, the genetic material (RNA) of the virus is extracted from the sample material (provided that the sample material contains the virus). Since the samples are collected from the nasopharynx of patients, the material required for analysis is gathered on a soft swab. Each swab is treated with a specific solution, which helps to transfer the sample material in liquid form from the swab into a small tube. The sample material is pipetted from tubes with patient-specific coding in groups of 96 onto a plate, where each sample is placed in a small round well. This plate includes samples from 93 individuals, plus 3 control samples (both positive and negative), in order to verify the accuracy of sample results on the given plate. Then the sample material is placed in the RNA extraction machine. It is interesting to note that at this stage, one lab technician works with no fewer than 93 people’s coronavirus samples at the same time! Once RNA is extracted from all 93 samples, the plate is sent off to a “clean room”, where they are once again pipetted onto a special plate with 384 wells. A chemical mixture of reagents is then pipetted onto them, containing the components necessary for the detection of the virus. The lab is capable of handling many individuals’ samples at once – one plate includes no fewer than 372 people’s samples; the remaining wells again contain control samples for quality check.

 DETECTING THE VIRUS

Virus RNA detection is used in Estonia as well as the rest of the world for detecting coronavirus, and in case of a positive result, the initial diagnosis of COVID-19. The plate with 384 samples, where RNA is extracted and mixed with reagents, is then placed by lab technicians into a PCR analyser. The analyser works based on the real-time PCR (Polymerase chain reaction) method and detects the possible virus in 372 samples within approximately a couple of hours. Once PCR analysis is over, the plate is disposed of as hazardous waste.

RECEIVING THE RESULT

The PCR analyser transmits the results into the laboratory information system (LIS) connected to the analyser. Then another quality check is performed. This ensures that each of the 384 samples on the plate goes through a positive as well as negative check for the virus, which verifies the purity and correctness of the analysis process. At this point, the senior lab technician of the given shift individually double-checks all the results issued by the analyser to verify their correctness once again. The results are then validated and inserted into the health information system. The laboratory also reports the results to the Communicable Disease Information System. Persons with an Estonian ID code and their family doctors can view the results from the moment of validation in the digilugu.ee environment. The SYNLAB Eesti laboratory is responsible for adhering to ISO 15189 quality standards for medical laboratories, and the Estonian Accreditation Centre has issued it with an Accreditation Certificate together with an Appendix (list of accredited methodologies).

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