Oncologica® video follows COVID-19 PCR swab through genomic lab test

For international travellers, taking their PCR test swab is only the beginning of the Coronavirus PCR test journey. 

In a meeting with Robert Courts MP, Minister for Aviation, Maritime & Security, Oncologica® explained the genetic science and logistics applied daily to thousands of PCR test swabs to determine positive or negative results.

Furthermore, the genomic sequencing of travellers’ positive PCR test results is vital for identifying high-risk COVID-19 variants of concern, to alert NHS Test and Trace and help prevent high-risk virus variants from entering the UK population across our borders.

To help guide the Minister through the PCR swab test journey, Oncologica® presented a video specially created to outline the keys stages of genomic testing and the impact this data driven approach is having on identifying and curbing high-risk variant transmission via incoming international travellers.

Step 1: The Coronafocus Covid-19 PCR Test Self-Swab Kit

A lot of work happens before PCR swab tests arrive for processing at Oncologica®’s specialist genomic testing laboratory. Travellers across the world first order PCR test kits online at A useful FAQ guide helps link travellers to government travel testing rules and details when kits are dispatched to coincide with PCR test date requirements. Coronafocus self-swab PCR test kits can be used for Pretravel-Fit to Fly, Day 2 Green list country and Day 2 Day 8 Amber list country arrivals and for Day 5 Amber list Test to Release certificates.

The COVID19 PCR test kits are dispatched by courier to customers and each kit includes a packaged self-sample swab, liquid tube with a unique barcode, sealable bag, swab instructions and a prepaid Royal Mail tracked return envelope(s). Travellers receive instructions electronically when placing their orders, explaining how to register and activate their PCR travel test kit by inputting the date and the time the swab was taken into the online customer dashboard prior to return of their kits to the lab for analysis.

Step 2: Sample return

Travellers can drop the PCR tests in the tracked return envelopes into Royal Mail priority post boxes located in every town or village , return the PCR sample(s) by hand to the 24/7 Oncologica® lab or contract their own private courier.

Step 3: The lab testing process

When a swab is returned to Oncologica®, scientists prepare the samples for COVID-19 PCR testing. They log the swab into the system with the unique sample number which tracks the PCR swab sample through the process and ensures that names are not directly on display.

The scientists prepare the samples for the Polymerase Chain Reaction (PCR). This checks whether the virus’s genetic information is present in the sample. The swab gets placed in a chemical solution that breaks apart and releases nucleic acids — the RNA whose unique sequences help identify the presence of the virus in a sample.

Coronavirus is a single-stranded RNA virus and needs to be converted into DNA using specific enzymes to enable the PCR process.

The PCR testing technique copies the genetic information and flags any matches with viral sequences.

We are all familiar with the DNA double helix. Each strand is made up of building blocks called nucleotides. PCR breaks these apart, into single strands in the solution. Then, strands of DNA that are custom-built to match the virus’s unique genetic sequences are introduced. If there is viral DNA in the sample, these primer strands will naturally latch onto the complementary strands. In this way, each strand of matching viral DNA gets doubled. The series of events keeps repeating to increase the amount of viral DNA, so that even tiny amounts of virus in the swab sample create copies.

When DNA primers bind with viral strands in the sample, they activate fluorescent signals that help track these genetic matches. In duplicating the viral DNA, every new strand of DNA creates a little light. The PCR doubles the strands in every cycle for exponential growth and light creation. The light cannot be seen by the human eye and is read by the PCR instrument. If a sample includes the virus, then the DNA primer strands bind, and lights accumulate to a level that signifies a positive test.

Step 4: The Results

Oncologica® have capacity to process up-to 40,000 PCR test swabs daily.  COVID-19 PCR swab test results are very specific and sensitive and are accessed via the online customer dashboard usually within 24 hours from booking the swab sample into the laboratory. This is to ensure individuals follow government guidelines to protect their health and prevent virus transmission to families and the wider public.

Step 5: Sequencing Positive Results

The UK’s Test and Sequence strategy requires any positive PCR test samples to be sequenced in government-accredited labs. Oncologica® is a leader in COVID-19 PCR testing and sequencing.


Our highly trained scientific and medical team use state of the art high-volume PCR and sequencing instrumentation to support the demands of the international travel testing programme.

The Integrated PCR testing and genomic sequencing strategy is pivotal in identifying emerging high-risk variants on a global scale. These variants can cross our borders rapidly, so sequencing them effectively detects and alerts NHS Test and Trace to emerging strains to help prevent them becoming prevalent in the population.  Sequencing is also important in monitoring vaccine efficacy, informing new vaccines designs and for protection from future escalating outbreaks.

Oncologica® PCR test options are detailed here