COVID-19 Testing: PCR (Diagnostic) vs Antibody

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COVID-19 Testing: PCR (Diagnostic) vs Antibody

News       About Us       Randox Health


18 June 2020

COVID-19 Testing: PCR (Diagnostic) vs Antibody

The advice from the World Health Organisation in relation to the COVID-19 pandemic has been simple; Test. Test. Test.

But what are the different types of COVID-19 tests and what are they used for?


Diagnostic (PCR) Testing

This type of testing detects SARS-CoV-2 (the virus that causes COVID-19) within the body and will tell you if you currently have COVID-19. PCR tests cannot tell you if you have had past infection.

Sample collection for a PCR test can vary, though it is usually in the form of a swab, which will gather an individual’s nasopharyngeal (nose and throat) secretions.

PCR tests for COVID-19 all use methods that detect a specific part of the viral genome – for example Viral RNA or Antigen.  

A sample is prepared by extracting the chosen section of the genome, and then PCR (Polyamerase Chain Reaction) techniques are used to amplify (replicate) the genome section, ready for detection.

Viral RNA Tests

This type of test detects the RNA (Ribonucleic acid) contained within the SARS-CoV-2 virus.

It is this type of test, for RNA, that is recommended by The World Health Organisation for COVID-19 diagnosis.

Antigen Tests

Antigens are molecular structures on the surface of viruses that are recognized by the immune system and are capable of triggering an immune response.

Antigen tests detect the presence of the SARS-CoV-2 virus by looking for the antigen on the surface of the virus.

Randox COVID-19 Test

The Randox COVID-19 test, as recommended by the World Health Organisation, detects the RNA contained within the SARS-CoV-2 virus.

After sample extraction and amplification, the virus is detected on our patented Randox Biochip Technology platform.

The Randox Biochip, which can run multiple tests simultaneously, performs two tests for COVID-19 – one specific and one confirmatory – as recommended by the WHO. This delivers extra assurance of the correct diagnosis and avoids the need to repeat the test.


Antibody (Serology) Tests

Antibody (also known as serology) tests, are usually performed on a patient blood sample, and look for antibodies (a type of protein) that may have been developed by the patient’s immune system to fight off disease.

If present, antibodies may provide a degree of immunity for the patient against COVID-19 in the future.

However, there is still much unknown about the body’s antibody response to COVID-19, including;

  • Whether all patients who have been infected with SARS-CoV-2 will generate antibodies (recent studies and news reports indicate that this isn’t the case. Click here for an example.)
  • Whether those who have had more severe symptoms as a result of COVID-19 will produce more antibodies than those who had mild symptoms, or were asymptomatic.
  • If antibodies from other coronaviruses previously experienced by the patient may be enough to fight off the virus, therefore eliminating the need for COVID-19 specific antibodies.
  • How long any COVID-19 specific antibody response will last for.
  • How much future immunity is provided by COVID-19 antibodies. Will it prevent the patient from being infected, or will future infection just be less severe?

If antibodies for the SARS-CoV-2 virus are present this can give an indication that the patient has been previously infected with COVID-19. Antibody tests do not confirm the real-time presence of the virus in your system.

For example, a negative antibody result does not necessarily mean the body has not been exposed to the SARS-CoV-2 virus. It could in fact, be currently infected, but has not yet generated antibodies. A diagnostic test will confirm current presence of the virus.


Therefore, it is recommended that antibody tests are used in tandem with a diagnostic test to determine a complete overview of the patient’s COVID-19 status.

Randox Health currently offers both diagnostic testing and antibody testing for SARS-CoV-2 (COVID-19).

A combination of diagnostic and antibody testing is available for individual purchase, or as part of our ‘Back to Business’ COVID-19 testing service, for staff screening.

Visit Randox Health to find out more.

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COVID-19 Laboratory Tools for Disease Management

News       About Us       COVID-19 Lab Tools

17 June 2020

COVID-19 – Laboratory Tools for Disease Management

In addition to tests for the detection of SARS-CoV-2, the virus that causes COVID-19, laboratory diagnostics play a pivotal role in patient management, risk stratification, monitoring of disease progression, associated complications and response to treatment.

Randox offers a comprehensive range of laboratory solutions including; diagnostics reagents, revolutionary Biochip technology and quality control designed to provide clinicians with valuable insights into disease severity ultimately helping to improve patient care.

Patients with comorbidities such as diabetes mellitus, cardiovascular disease (CVD) and chronic kidney disease (CKD) are particularly susceptible to COVID-19 infection and are at greater risk of developing severe illness.  The Randox portfolio may also be used to diagnose and monitor such at risk patients with underlying health concerns.


Biochemistry Reagents

Our extensive test menu comprises 113 assays, including many unique tests and a range of biomarkers designed to assist laboratories when screening for a variety of COVID-19 related health issues.

Randox Reagents are internationally recognised as being of the highest quality; producing accurate and precise results.  Applications are available detailing instrument-specific settings for the majority of clinical chemistry analysers.

C-Reactive Protein (CRP)

Elevated markers of inflammation and infection such as CRP may indicate severe viral infection. CRP is elevated in up to 86% of COVID-19 patients who are admitted to hospital. Testing for CRP is useful in assessing prognosis, and when monitoring improvement. It is recommended that CRP is measured at baseline and then at intervals, a sudden increase in levels will prompt surveillance for secondary infection or other cause of deterioration.


As an acute phase reactant, Ferritin levels increase in response to inflammation. High levels have been identified in approximately 60% of individuals hospitalised as a result of COVID-19 infection. In critically ill patients, elevated Ferritin levels may be indicative of a cytokine storm and secondary haemophagocytic lymphohistiocytosis, a hyperinflammatory syndrome associated with organ failure.

Liver Function Tests (Albumin, ALT, AST, Bilirubin)

Patients with COVID-19 may be at higher risk of liver injury or impairment of liver function. Liver function markers such as ALTAST and Bilirubin are notably higher in more severe infections, decreased albumin levels have also been documented in severe cases. Drug induced liver injury as a result of COVID-19 treatment should not be ignored and should be monitored.

Renal Function Tests (Creatinine, Cystatin C)

Emerging evidence suggests that SARS-CoV-2 may directly affect kidney function, as such COVID-19 patients should be assessed for Acute Kidney Injury (AKI) on admission to hospital and monitored throughout their stay. AKI can lead to worse outcomes for patients.

Lactate Dehydrogenase (LDH)

LDH levels may be a convenient marker for the identification of COVID-19 patients at higher risk of developing severe respiratory failure. It is well documented that high LDH levels are indicative of haematological malignancy and acute lung injury. LDH levels might therefore reflect tissue necrosis related to immune hyperactivity and thus are related to poor clinical outcomes in individuals with COVID-19.


Chloroquine has been investigated as a potential treatment for COVID-19, the anti-malaria drug however could have devastating consequences for those with a G6PDH deficiency. G6PDH deficiency is a genetic disorder affecting the red blood cells, causing them to break down prematurely. The most common complication of deficiency is haemolytic anaemia. An estimated 400 million people globally have G6PDH deficiency, it is most common in certain parts of Africa, Asia, the Mediterranean and Middle East.


Randox Biochip Solutions

Randox Biochip technology is extremely versatile with applications in not only the diagnosis of COVID-19 but also the identification of individuals at risk of developing more severe illness.  

Unique to Randox, Biochip technology is capable of simultaneous detection of a panel of  related disease markers.  An extensive range of  Biochip panels are available, each optimised to provide the best performance.

Cytokine Arrays

Cytokines play a vital role in the immune system and are known to be involved in the body’s response to a variety of inflammatory and infectious diseases. The over stimulation of these cytokines in response to infection is referred to as a ‘cytokine storm’ and strongly correlates with poor disease outcomes. Cytokine storms are a common complication of SARS-CoV-2 infection triggering viral sepsis, where viral replication and excessive, uncontrolled systemic inflammation may lead to pneumonitis, Acute Respiratory Distress Syndrome (ARDS), respiratory failure, shock, multiple organ failure, secondary bacterial pneumonia, and potentially death. Cytokines such as IL-6 appear to be elevated in patients with more severe illness and may be used to monitor response to treatment as levels decrease as the condition improves.


Quality Control Solutions

Randox offer a range of Quality control and External Quality Assessment (EQA) solutions designed to ensure the accuracy and reliability of patient testing.


Decreased blood counts have been frequently identified in COVID-19 patients and may be indicative of a decreased immunological response to the virus, bacterial infection or consumption.

Blood Gas

Blood Gas tests are used to help diagnose and monitor critically ill patients in intensive care units (ICU) and emergency departments. Blood Gas testing continues to play a critical role in the management of COVID-19 patients providing an indication of a patient’s oxygenation levels. Monitoring of these levels will enable healthcare professionals to make ventilator adjustments if required.

Cardiac Markers

Increased levels of cardiac markers including Troponin and CK-MB may be associated with a higher mortality rate in COVID-19 patients.


Patients with severe COVID-19 infection are more likely to have coagulopathy, a condition in which the bloods ability to form clots is impaired. Activation of blood coagulation factors such as Prothrombin Time (PT) and D-dimer are significant predictors of disease severity and mortality.


Procalcitonin is an acute phase reactant released by most tissues during inflammation and is particularly associated with bacterial infection. Although it is not usually elevated in viral infections such as SARS-CoV-2 levels may increase as a result of severe systemic inflammation. It may also be used to help detect secondary infections.

For further information about any of the above Laboratory Tools for COVID-19 Disease Management please email


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Cytokine testing for COVID-19 risk stratification and treatment monitoring

News       About Us       Cytokine Biochips


11 June 2020

Cytokine testing for COVID-19 risk stratification and treatment monitoring

On Biomedical Science Day 2020, an innovative method of monitoring treatment efficacy and recovery of COVID-19 has been unveiled by global diagnostics company Randox Laboratories.

The test, which looks for the presence of cytokines (a type of small protein) is performed on Randox’s patented Biochip Technology, which can simultaneously detect multiple analytes from a single patient sample.

Cytokines play a vital role in the immune system and are known to be involved in the body’s response to a variety of inflammatory and infectious disease, such as COVID-19.

Lynsey Adams, Randox Marketing Manager, commented;

“Cytokine storms, which are the overstimulation of cytokines in response to infection, are a common complication of severe cases of COVID-19, and can trigger excessive, uncontrolled systemic inflammation.

“The monitoring of cytokine proteins therefore offers a unique opportunity to identify patients who, as a result of this viral sepsis, are at risk of poor disease outcomes including pneumonitis, Acute Respiratory Distress Syndrome, respiratory failure, shock, or even organ failure.

“Treatment for any infection, COVID-19 included, is most effective when administered at an early stage, and so the detection of cytokine storms within COVID-19 patients could provide vitally important information that will direct the appropriate patient care pathway and facilitate improved patient outcomes.”

The comprehensive cytokine testing menu from Randox comprises of 26 different cytokines, across four different biochip panels.

Designed to make cost, time and resource savings for a range of diagnostic laboratories, Randox Cytokine Biochips can detect up to 12 cytokines and growth factors from a single patient sample.

Lynsey continued;

 “The multiplex capabilities of the Randox Biochip will provide clinicians with a more comprehensive picture of the patient’s condition.

“Compatible with our Evidence and Evidence Investigator analysers, which are capable of processing 2960 and 2376 tests per hour respectively, Randox Cytokine Biochip panels offer a comprehensive testing method for these proteins which play such a central role in the immune system.”

In addition to COVID-19 risk stratification, cytokine testing has also been linked to monitoring for allergies, vascular diseases, cancer, and a range of autoimmune diseases.

Key Benefits of Randox Cytokine Testing

  • Simultaneous detection of up to 12 cytokines and growth factors from a single patient sample
  • Fully automated and semi-automated testing platforms available to suit all laboratory throughputs
  • Comprehensive test menu comprising 26 cytokines, cytokine receptors and growth factors
  • Suitable for use with serum and plasma samples
  • Excellent analytical performance
  • Availability of complementary quality controls for a complete testing package

For more info please visit, email or phone 028 9442 2413

Want to know more about Randox?

Contact us or visit our homepage to view more.

Our Randox Products and Services





Raising awareness of sexual health on National STIQ Day

National STIQ Day

National STIQ day was introduced in 2010 and every year since then the 14th of January has been dedicated to raising awareness for STIQ.  The purpose is to emphasize the importance of sexual health and to encourage everyone to get regular health checks.

Sexually Transmissible Infections (STIs) are infections passed from one person to another through unprotected vaginal, oral, or anal sex, or genital contact.

Lack of symptoms

More and more people in the UK are catching STIs and each year the infection rate is rising. According to The World Health Organization (WHO), more than 1 million STIs are acquired every day and the majority of these STIs have no symptoms.1 Therefore you could have an STI and not be aware. 70% of women and 50% of men show no symptoms after contracting Chlamydia which is the most common STI condition in the UK.

Even though the majority of the time symptoms of STIs aren’t visible, there can be signs of having an STI, including unusual discharge from the vagina, penis or anus, pain when peeing, lumps or skin growth around the genitals, a rash, unusual bleeding, itchiness or blisters around the genitals.3

What to do when you catch an STI

Anyone can catch an STI regardless of what age you are, your sexuality or how many sexual partners you have, as it only takes one sexual encounter to put you at the risk of catching an STI. A shocking fact from Public Health England shows that a case of chlamydia or gonorrhea is diagnosed in a young person every 4 minutes in England, and over 144,000 diagnoses of these sexually transmitted infections are seen in people aged 15 to 24 in 2017. 4

It is extremely important to get routinely tested. The earlier the diagnosis is made and treated the less chance of having long-term effects including infertility.

Randox Biosciences 10-plex STI test

Randox Biosciences would like to take the opportunity to support STIQ day by offering our CE marked 10-plex STI test, a cost-effective solution for accurate STI testing. This test detects the following 10 infections simultaneously from a single patient urine sample.

  • Neisseria gonorrhoea (NG)
  • Mycoplasma genitalium (MG)
  • Ureaplasma urealyticum (UU)
  • Chlamydia trachomatis (CT)
  • Trichomonas vaginalis (TV)
  • Haemophilus ducreyi (HD)
  • Mycoplasma hominis (MH)
  • Treponema pallidum (TP)
  • Herpes simplex virus 1 (HSV-1)
  • Herpes simplex virus 2 (HSV-2)

Does your laboratory or clinic carry out STI testing? Our molecular analyser, the Bosch Vivalytic, powered by our award winning Biochip Array Technology, could be the diagnostic solution.

For more information about our STI Arrays or Vivalytic email:





Discussing Companion Diagnostics with Dr Miguel Quesada-González

You may have heard of Companion Diagnostics. This type of diagnostic provides information that is essential for the safe and effective use of a corresponding drug or biological product. It can help to stratify groups of patients which will respond safely to a clinical drug trial, and those who may suffer undesirable side effects.

But why are Companion Diagnostics useful?

Randox Biosciences Pharma Relationship Manager Dr Miguel Quesada-González, PhD has the answer.

“As part of my new role, I’ll be supporting drug development and clinical trials. So as a scientist by background (the nature of the beast) I’ve been reading into and researching this incredibly interesting area of science.

“Since Day 1, Companion Diagnostics (CDx) especially caught my eye.

“When it comes to new drug development, either for Pharma or Biotech, there are many benefits of running a CDx. Based on well-acknowledged scientific papers that I have read, and my own personal perception of the current situation, I’d like to summarise and simplify in just 2 bullet points, what I personally believe to be the most important benefits of running a CDx.

“(a)  Delivering the right treatment to the right patient at the right time.

“We should never forget that our priority is the health and integrity of patients. It’s been proven that patients who have similar diagnoses very often respond differently to the same treatment. This variability presents a risk in both the efficacy of the treatment and the safety of the patient.

“The development of a drug is already a risky, long and costly process, so wouldn’t you like to avoid the initial high risk by having a good defined target initially?

“(b)  Saving time.

“Money is valuable but time even more so. Time is precious and priceless. Once it’s gone, there’s nothing we can do about it!

“The smaller and more targeted the clinical trials are, the less time and resources you’ll be spending. Normally, the CDx is not initiated until a drug has reached the later stages of development, but, actually, if you put the CDx in place at early development stages (preclinical) it presents many advantages because it enables the selected biomarker to be validated and determined before large amounts of resources have been put in place.

“The faster a potential treatment is developed and approved, the more people you can save, cure or simply improve their quality of life.”

For further information on Companion Diagnostics from Randox Biosciences please email us at

Dr Miguel Quesada-González, PhD, Randox Biosciences Pharma Relationship Manager






The Evidence Evolution – The newest member of the Evidence series

Launched in 2016, the Evidence Evolution has set new standards in the world of clinical, forensic and food testing.

With the most extensive test menu on offer, we can provide more tests than any other supplier and we are continually investing in R&D to keep up with industry developments and challenges, such as our extensive clinical test menu with a range of routine and novel tests including our CKD panel which detects the early stages of Chronic Kidney Disease.

The Evidence Evolution utilises Randox’s cutting-edge Biochip Array Technology, offering diagnostic testing from a single sample. The Evidence Evolution boasts 2640 tests per hour and when put to the test against our competitor machines, the Evidence Evolution gives a true walk away time of up to 2 hours, meaning staff can fully load the machine and get up to 44 results from each sample every minute, while they get on with important laboratory tasks.

The Evidence Evolution has been designed to meet the needs of a variety of laboratories. Delivering quality results, efficiently and economically in forensic and clinical immunoassay locations.

The Evidence Evolution is the latest development in our Evidence Series range, which was first launched in 2002. This trusted technology is powered by Biochip and is used throughout the world in a range of different sites for clinical, toxicology and food testing. The Evidence Series has a range of analysers that can meet the need of any laboratory.

For more information on any of the Evidence Series analysers, please visit or contact us





Is Biomarker Multiplexing the future of kidney disease screening?

Chronic Kidney Disease (CKD) is both a cause and a consequence of cardiovascular diseases, and is an increasing burden on global health. As diabetes, obesity and hypertension incidences continue to rise and the world’s population steadily ages, CKD’s prevalence is already estimated to be between 11% and 13% globally for all five KDOQI stages, with a majority in Stage 3 (about 90% of all stages).

With early stages of CKD being asymptomatic and current diagnostic tools (proteinuria determined by albumin to creatinine ratio and decreased renal function estimated from GFR using the CKD-EPI equation) are insufficiently sensitive to detect most cases up to stage 3, it is likely that the true prevalence of CKD is still underestimated. Therefore the need to improve both early diagnostics and overall CKD outcome is all the more critical.

Accordingly, biomarker research has been intense in the field of renal disease for at least 10 years with a number of promising candidates emerging, some now well-known by specialists: Cystatin C, NGAL or KIM-1 for example.

However, further novel biomarkers, assessed in combination using a properly developed multiplex assays can allow superior insight into CKD than what their individual performance could achieve.  This also largely stems from selecting the markers that are indicative of complementary mechanisms that contribute to the development of CKD.

When assayed together from a single serum sample and after combinatorial analysis has been applied, these biomarkers can open new avenues in the management of CKD, such as proper diagnosis of the condition from Stage 1, clear differentiation between stages and monitoring of the progression pace of the disease. Early screening of patients at risk of CKD is now within reach and it is expected that its systematic use will have a profound impact on health system economics.

Another area of interest in renal research is Acute Kidney Injury (AKI) which may arise as a result of cardiac surgery and can subsequently lead to CKD. AKI detection is also of significant interest in the field of drug development, where early stage toxicity is still a large cause of new drug marketing withdrawal. Hence selecting and qualifying kidney tissue damage biomarkers, and assembling them into a multiplex panel is a key priority to those involved in early stage clinical trials.

An AKI panel has been worked out using the same principles as those used in the development of the CKD panel: high individual diagnostic value and multiple, independent cellular targets. This panel is now ready for final clinical qualification and will be one of the first of several organ-targeted safety panels aiming to become standard for drug induced toxicity screening.

It is key to the adoption of multiplex testing that proper validation guidelines be published and that careful, matrix-based validation data is made available to potential users. It is essential that multiplexed testing comes to the front line of testing in the field, so it can deliver to its full potential and start translating into public health improvement and cost savings. Technology is ready, let’s make a start!

Dr Claire Huguet

Randox Biosciences – Head of Biomarkers


For further information about kidney disease screening from Randox Biosciences, please contact




Biochip Carrier Applications in the Randox Evidence Series

Biochip Array Technology is the fundamental component which drives the Randox Evidence Series immunoanalysers. The simultaneous detection of multiple analytes from a single sample allows for a complete patient profile, providing exceptional time, resource and cost savings.

The Evidence Series analysers all carry the Biochip in different applications. In order to gain a better understanding of how it is utilised, the illustrations below demonstrate how adaptable and flexible the technology is across the Evidence Series.

Evidence Evolution

  • One strip contains 10 biochips
  • Analyser can hold 20 strips
  • Can produce a throughput of up to 2640 tests per hour


  • Each cassette contains 10 carriers
  • Each carrier has 9 wells
  • Analyser can hold 4 cassettes at once
  • Can produce a throughput of up to 3960 tests per hour

 Evidence Investigator

  • Analyser holds 1 cartridge
  • 1 cartridge contains 9 wells
  • Thermoshaker capable of carrying 6 cartridges
  • Can produce a throughput of up to 2376 tests per hour

 Evidence MultiSTAT

  • Analyser holds 1 cartridge
  • Cartridge comes pre-loaded with reagents and QC
  • Can produce a throughput of up to 132 tests per hour


About the Randox Evidence Series

The Evidence Series is set to revolutionise diagnostic testing forever. Offering unrivalled capabilities across all analysers, we truly believe that the Evidence Series range of immunoassay analysers can meet your diagnostic testing capabilities.

For more information on any of the Evidence Series analysers, visit or contact us




Evidence Investigator – Biochip Immunoanalyser

Adaptable, Efficient & Comprehensive

The #1 choice for research, clinical, forensic, molecular, and veterinary testing.

Using the same multiplexing technology as the fully automated Evidence, the semi-automated benchtop immunoanalyser Evidence Investigator is suitable for medium throughput laboratories. In addition to its current wide test menu new tests are in development.

A revolution in diagnostics, the Evidence Investigator has the capability to maximise the efficiency of your laboratory.


Features & Benefits

  • Semi-automated benchtop immunoanalyser
  • Up to 2376 tests per hour
  • Up to 44 analytes screened per biochip
  • Suitable for medium throughput laboratories
  • Extremely robust with only one moving part
  • 75cm (H) x 48cm (D) x 42cm (W)

Available BAT Arrays

  • Adhesion Molecules Array
  • Alzheimer Risk Detection Array
  • Anthelmintics Array
  • Antimicrobial Arrays
  • Beta-lactam Array
  • Cardiac Array
  • Cardiac Risk Prediction Array
  • Cerebral Arrays
  • Chronic Kidney Disease Array I & II
  • Coccidostats Array
  • Cytokine Arrays
  • Drugs of Abuse Arrays
  • Endocrine Array
  • Familial Hypercholesterolemia Arrays
  • Gastro Intestinal Panel 1 and 2
  • Growth Promoter Arrays
  • KRAS, BRAF, PIK3CA* Array (*for research use only)
  • Metabolic Syndrome Arrays
  • Respiratory Multiplex Array
  • SARS-CoV-2 IgG (RBD & NP) Array
  • STI Multiplex Array
  • Synthetic Steroids Array
  • Thyroid Free Array
  • Thyroid Total Array
  • Tumour PSA array
  • Vitamin D Array


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  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
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