PEKIN — About 15,000 specimens are tested for COVID-19 daily at Reditus Laboratories in Pekin. These specimens come from testing sites throughout the state.
Here is a summary of the process.
A phlebotomist/lab assistant administers the nasal swab specimen collection or proctors the specimen collection if it is self-administered by the patient. In this photo, Jack Knight, of Morton, an employee of Peoria Public Schools District 150, is swabbed by Billie Jo Nebergall, a phlebotomist/lab assistant, on Jan. 12, 2021.
After the patient specimen and information is delivered by courier to Reditus, specimens are prioritized based on patient urgency. For example, specimens from hospitals and long-term care facilities are processed before specimens from community-based testing sites. With each patient specimen, an accessioner takes the specimen and inputs the patient specimen order information into the Reditus system. Then, the accessioner creates a label for the specimen vial. Here, accessioner Joshua Stonewall inputs information for Jack Knight’s specimen.
Next, another accessioner scans patient information into the computer and places the vial in a rack. In the photo, accessioner Clarice Mason scans Knight’s vial.
The rack and a corresponding sample map are taken into the molecular laboratory where a molecular lab technician, such as Karina Champion in the accompanying photo, transfers patient specimen into a sample plate for the viral RNA to be extracted. From there, sample plates are placed in an instrument that uses a two-step wash process to extract the viral RNA from the specimens.
Next, medical technologists, such as Wendy Wagner in the accompanying photo, make the reaction mix, which contains the primers and probes that are directed to detect the virus, and places it into 384 wells of a reaction plate.
Patient specimens are then transferred to that reaction plate. Reaction plates are taken to the Quant Studio Room, where the plate is mixed and centrifuged, and then placed on a real-time PCR (polymerase chain reaction) analyzer called the Quant Studio. The PCR analyzer tests for three genes. Two of the three must be present for a person to test positive for COVID-19. In the accompanying photo, April Robley, lead first shift lab technician, uses the real-time PCR analyzer.
Finally, patient PCR curves are analyzed in the molecular lab to determine whether or not COVID-19 is detected. In the accompanying photo, lab technician Jessi Edmondson analyzes patient data.
The testing process at Reditus Laboratories takes four to six hours, said Michelle Anderson, clinical molecular lab manager.
The amount of time from when the patient specimen is collected until tests results are known depends on where the specimen is collected in Illinois and must allow for time for the specimen to be delivered by Reditus courier to the lab, Anderson said. Reditus Laboratories provides COVID-19 testing for many hospitals, long-term care facilities and state testing sites. Reditus aims for less than 24 hours on stat (urgent) specimens and less than 48 hours from community-based testing sites. During times of large surges in testing, that goal is more difficult to attain. But Reditus lab technologists are working 24 hours a day, seven days a week, and put in overtime as needed to get testing done as quickly as possible.
By Paul Swiech
Reditus Laboratories uses gold-standard PCR testing for SARS-CoV-2 detection. While antigen testing and saliva-based testing have become more readily available, these sampling sources/testing strategies have limitations which increase the risk of providing false-negative test results.
PCR Testing is real-time reverse transcriptase polymerase chain reaction (RT-PCR) to detect viral nucleic acids in extracted clinical samples of the upper respiratory tract, nasopharynx, anterior nares and bronchoalveolar lavages (BAL).
Nasopharyngeal (NP), nasal and BAL specimen collection have less variability than other collection types (i.e. saliva) and are the preferred specimen types by the U.S. Centers for Disease Control and Prevention for detecting SARS-CoV-2. Gene targets specific to SARS-CoV-2 are detected in real time with a final result based on the presence or absence of these genes. PCR has sensitivity and specificity of 98% or greater for COVID-19 by detecting unique gene sequences present only in SARS-CoV-2. A multiplex Influenza A, Influenza B, SARS-CoV-2 assay is on the horizon and can be simultaneously tested from the approved upper respiratory collected specimens.
Saliva-based testing. Several groups have received emergency use authorization for testing COVID-19 using saliva as an alternative sampling source. Saliva-based testing has a 75% to 91% overall sensitivity in detecting SARS-Co-V-2 RNA. Collection of saliva from patient specimens requires no eating, drinking, smoking, brushing of teeth and mouthwash for a minimum of 30 to 45 minutes prior to the sample collection because these can decrease the sensitivity of COVID-19 detection. Studies of saliva-based testing are limited and have not compared NP and saliva results from controlled populations. Studies have been performed using samples from symptomatic patients, so data is limited for accuracy in detecting COVID-19 in asymptomatic individuals. In addition, saliva-based assays are not approved for testing Influenza.
Antigen testing, like PCR, requires nasal or NP collection. Antigen testing, also known as Rapid Testing, is quick but isn’t as sensitive as PCR because antigens/proteins aren’t amplified for detection. Thus, PCR, which amplifies nucleic acid, can detect fewer copies of RNA than antibodies can detect protein in a sample.
COVID-19 Sites – You can retrieve a current list of State of Illinois testing sites by go to dph.illinois.gov/testing.
We do not accept walk-ins for testing at our location. Please go to the dph.illinois.gov/testing
You must be registered to access our Portal. To register you mush speak to your Account Manager and they will review the process establish training and give you access to the portal.
To order testing supplies you must contact your Account Manager.
If there is an issue with your result documentation please talk to your Account Manager.
You can call 866-736-0002 and they will transfer you to the contact person.
You can send an email to [email protected]
We bring pathology services to 16 healthcare facilities in central Illinois and eastern Iowa.
We provide results and vital information to physicians in diagnosing illness.