Your outsourcing solution enhanced by Randox Biochip Array Technology
Randox Clinical Laboratory Services (RCLS) strives to provide a clinical laboratory service to meet the time sensitive, bespoke requirements of research and clinical projects globally.
RCLS utilises the expertise and knowledge Randox has built up over 35 years producing high quality IVD products. Many years of development and the expertise of highly qualified scientists from Randox has been invested to create the Biochip Array Technology (BAT) – a multi-analyte testing platform facilitating the simultaneous quantitative or qualitative detection of a wide range of analytes from a single sample.
Biochip Array Technology provides a unique platform for assessment of biological samples in a rapid, accurate and easy to use format and users can have the utmost confidence in this proven technology.
A chemically activated 9x9mm ceramic biochip acts as a solid phase reaction vessel. Biochips are pre-fabricated with discrete test regions (DTRs); a different antibody/oligonucleotide is immobilised at each spatially distinct DTR. Up to 49 individual DTRs can be arrayed on to a single biochip with one biochip per sample used to generate multiple results simultaneously.
This eliminates the need to run costly, time consuming and sample intensive single analyte assays. The biochip detection is based on a chemiluminescent signal emitting light, without heat, as a result of a chemical reaction. The light emitted is simultaneously detected and quantified using a CCD camera.
Overall, by utilising Randox Clinical Laboratory Services you can save your laboratory time and money. Due to our multiplex panels we offer a cost-effective, labour-saving and time-reducing solutions for your sample testing. As a result we provide your laboratory with the best solution to outsource your sample.
If you would like to find out more information about RCLS you can visit www.randox.com/rcls
Or for any additional questions on what it has to offer you can email the RCLS team at firstname.lastname@example.org
Randox were proud to sponsor four awards at the Liverpool Guild of Students Awards 2018 which took place on Friday 27th April in the city’s Mountford Hall. Now in its tenth year, the prestigious occasion recognises individuals or groups who have gone above and beyond the call of duty to help fellow students and the wider community while improving student experience at the University of Liverpool.
The ceremony was attended by 300 students nominated from Liverpool Guild of Student’s 22,000 student member body, along with key university staff members. Liverpool University is privileged to enjoy such a vibrant and active student culture in the city which made for tough competition in each of the awards categories.
The categories sponsored by Randox were in the Development category block;
Campaign of the Year – the Liverpool University Marine Biology Oceanography and Ecology Society won this award after they developed a campaign to reduce plastic impact on-campus as well as helping the general public to become more knowledgeable on the issue.
The Development Award – Congratulations to the Liverpool Paediatric Society who received this award. The society has fully committed to providing high quality academic, skills based sessions for their members. As well as fundraising for nominated charities throughout the year, they also provide excellent opportunities for members to learn new skills to help them both in their studies and future careers.
The Innovation Award – the National Hindu Students’ Forum Liverpool won the award for innovation after they built on the success of their previous committee members and raised over £400 for MIND by transforming a once small-scale event, Asha, into a large-scale event with stalls, raffles, performances and a three course meal.
The Challenge Award – the Feminist Society at the University of Liverpool has promoted inclusivity and broadened the reach of the Guild outside of the university campus. They have hosted a wide variety of fundraisers and club nights not only to raise funds for charities but also to educate attendees on sexual violence.
Dr. Peter FitzGerald, Managing Director of Randox, commented on the sponsorship;
“Through our own world-leading research and development in the field of health diagnostics, we are making a difference both locally and worldwide to improve health and extend lives. Development is one of the most fundamental areas in the modern era as we move forward, break boundaries and expand in to new territories and technologies in health research and diagnostics.
“Our sponsorship of the Development category at the Liverpool Guild of Students Awards – the Campaign of the Year, Innovation, Challenge and Development awards – signals our commitment to the future of research and the importance of both new ideas and talent for the future of science and beyond.”
Glen Whitcroft, Media Sales Manager at the Liverpool Guild of Students, said;
“We were incredibly proud of the achievements of our students. The positive difference they have made to their campus and communities is immeasurable and having a world-leading company such as Randox recognising their hard work by sponsoring four of our awards at the Liverpool Student Guild last week was a privilege. Randox is a company well-known for its encouragement of young talent through its second-to-none placement and graduate opportunities in a variety of disciplines from science and technology to engineering, marketing and even graphic design. We’re delighted to partner with a company who places such value on the importance of student and graduate positions.”
For more information on the Liverpool Guild of Students Awards available please email email@example.com or phone 028 9442 2413.
Lp(a) is an independent risk factor for cardiovascular disease (CVD), even when classical risk factors such as hypertension, elevated cholesterol, and diabetes have been taken into consideration. High levels of Lp(a) is a heredity condition, associated with complex mechanisms involving the proatherogenic and prothrombotic pathways (1).
Traditional CVD testing panel
According to the World Health Organisation (WHO), CVD is the leading cause of death globally, accounting for 31 percent of deaths, totalling 17.7 million deaths per year. 80 percent of all CVD deaths are attributed to heart attacks and strokes, equivalent to 1 in 4. Identifying those who are at a high risk of developing CVD and ensuring that they are receiving the appropriate treatment can prevent premature deaths (2).
The lipid profile is frequently used to assess an individual’s risk of CVD developing later in life. Routine tests to assess CVD risk include: triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). LDL-C has been found to strongly correlate with CVD risk (3). NICE recommend measuring total cholesterol, HDL cholesterol, non-HDL cholesterol and triglycerides as the full lipid profile and then review other risk factors, including: age, diet, smoking, QRISK, co-morbidities to view risk and the management of risk (4). However, the current lipid panel needs to be adjusted to ensure that its utilisation is effective in meeting clinician and patient needs.
Lipoprotein (a) or Lp(a) consists of two protein molecules, apolipoprotein (a) or apo(a) is covalently linked by a disulphide bond to the apolipoprotein B-100 or apoB-100 of a cholesterol-rich low-density lipoprotein or LDL like particle. Lp(a) is synthesised in the liver and is detectable in the bloodstream (5).
The structure of Lp(a) resembles that of the proteins involved in the breakdown of blood clots, plasminogen and tissue plasminogen activator (TPA). As a result, the biggest concern with Lp(a) is that it prohibits the ability of these proteins to break down blood clots by competing for the ‘binding to fibrin’, boosting the blood’s clotting ability within arteries, thus heightening the risk of heart attacks and strokes. Consequently, high levels of Lp(a) is characterised by atherosclerosis including coronary heart disease, peripheral vascular disease, aortic stenosis, thrombosis and stroke (6).
The Journal of the American Medical Association reviewed 36 studies in 2009 which assessed ‘the role of Lp(a) and vascular disease’ in 126,634 individuals. The study found that a 3.5-fold increase in Lp(a) levels was accompanied with a 13 percent higher risk of coronary heart events and a 10 percent higher risk of stroke (7).
Later, an Italian population study carried out on 826 individuals in 2014 found that elevated levels of Lp(a) is due to two different variations of the apo(a) gene which is determined by the kringle sequence differences at the apo(a) locus. The study found that individuals with one variation had a 50 percent greater risk of CVD, while individuals with both variations had 2.5 times greater risk (7).
According to the Lipoprotein Foundation (2015), based on genetic factors, from birth, one in five or 20% of individuals have high Lp(a) levels greater than 50mg/dL, with most blissfully unaware they have it. Overtime, high levels of Lp(a) gradually narrow the arteries, limiting blood supply to the brain, heart, kidneys and legs, increasing the risk of heart attacks and strokes (5).
Testing for high Lp(a) levels
The Lipoprotein (a) Foundation (2015) recommends that Lp(a) levels should be tested if:
- There is a family history of cardiovascular disease including stroke, heart attack, circulation problems in the legs and/or narrowing of the aorta, at a young age
- Stroke or heart attack if classical risk factors including high LDL-cholesterol, obesity, diabetes and smoking have been eliminated
- High levels of LDL-cholesterol following treatment with statins or other LDL lowering medications(5)
When selecting a Lp(a) assay, the Internal Federation of Clinical Chemistry (IFCC) (2004) Working Group on Lp(a) recommends that laboratories use assays that do not suffer from apo(a) size-related bias to minimise the potential risk of misclassification of patients for coronary heart disease (8).
The Lp(a) Foundation reference Marcovina and Albers (2016) in their recommendations for the best Lp(a) test. The study came to the following conclusions:
- Robust assays based on the Denka method, reportable in nanomoles per litre (nmol/L) are traceable to WHO/IFCC reference material
- Five-point calibrators with accuracy-based assigned target values will minimise the sensitivity of to the size of apo(a)
- Upon request, manufacturers should provide the certificate of evaluation of the calibrator and reagent lots with the relative expiration dates (9)
Benefits of the Randox Lp(a) assay
The Randox Lp(a) assay is one of the only methodologies on the market that detects the non-variable part of the Lp(a) molecule and so suffers minimal size related bias providing more accurate and consistent results. This methodology allows for the detection of Lp(a) in serum and plasma. The Randox Lp(a) kit is standardized to the WHO/IFCC reference material, SRM 2B, and is the closest in terms of agreement to the ELISA reference method.
A five-point calibrator is provided with accuracy-based assigned target values which accurately reflects the heterogeneity of isoforms present in the general population.
Liquid ready-to-use reagents are more convenient as the reagent does not need to be reconstituted, reducing the risk of errors.
Applications are available for a wide range of biochemistry analysers which details instrument-specific settings for the convenient use of the Randox Lp(a) assay on a variety of systems. Measuring units in nmol/L are available upon request.
- Li, Yonghong, et al. Genetic Variants in the Apolipoprotein(a) Gene and Coronary Heart Disease. Circulation: Genomic and Precision Medicine. [Online] October 2011. [Cited: April 24, 2018.] http://circgenetics.ahajournals.org/content/4/5/565.
- World Health Organisation. Cardiovascular Disease. [Online] 2017. [Cited: April 30, 2018.] http://www.who.int/cardiovascular_diseases/en/.
- Doc’s Opinion. Lipoprotein (a). [Online] 2013. [Cited: April 30, 2018.] https://www.docsopinion.com/health-and-nutrition/lipids/lipoprotein-a/.
- National Institutional for Health and Care Excellence. Cardiovascular disease: risk assessment and reduction, including lipid modification. [Online] July 2014. [Cited: April 30, 2018.] https://www.nice.org.uk/guidance/cg181/chapter/1-recommendations#lipid-modification-therapy-for-the-primary-and-secondary-prevention-of-cvd-2.
- Lipoprotein(a) Foundation. Understand Inherited Lipoprotein(a). [Online] 2015. [Cited: April 24, 2018.] http://www.lipoproteinafoundation.org/?page=UnderstandLpa.
- Heart UK. Lipoprotein (a). [Online] June 23, 2014. [Cited: April 24, 2018.] https://heartuk.org.uk/files/uploads/huk_fs_mfss_lipoprotein_02.pdf.
- Ashley, Robert. High lipoprotein(a) levels may indicate heart disease in some. The Brunswick News. [Online] March 05, 2018. [Cited: April 24, 2018.] https://thebrunswicknews.com/opinion/advice_columns/high-lipoprotein-a-levels-may-indicate-heart-disease-in-some/article_16ab1049-7a6f-5da0-8966-59e94ae31b6d.html.
- Dati, F; Tate, J R; Marcovina, S M; Steinmetz, A; International Federation of Clinical Chemistry and Laboratory Medicine; IFCC Working Group for Lipoprotein(a) Assay Standardization. First WHO/IFCC International Reference Reagent for Lipoprotein(a) for Immunoassay–Lp(a) SRM 2B. NCBI. [Online] 2004. [Cited: April 30, 2018.] https://www.ncbi.nlm.nih.gov/pubmed/15259385.
- Tsimikas, Sotirios. A Test in Context: Lipoprotein(a) – Diagnosis, Prognosis, Controversies, and Emergining Therapies. 6, s.l. : Elsevier, 2017, Vol. 69. 0735-1097.
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 firstname.lastname@example.org
Most newborns enter the world healthy. But sometimes, infants develop conditions that require medical tests and treatment. Newborns are particularly at risk for some diseases, and in particular infections, because their immune systems aren’t developed enough to fight bacteria, viruses, and parasites.
At Randox we offer a number of accurate and reliable tests capable of detecting illnesses in newborn babies, enabling early medical intervention to allow for the best possible outcome for the baby.
Testing for Jaundice with Randox Bilirubin
In the routine care of newborns, a test for bilirubin is commonly conducted.
Bilirubin is formed by the breakdown of haemoglobin in the spleen, liver and bone marrow. It travels to the liver where it is secreted into the bile ducts as bile, and stored in the gallbladder where it is later released into the small intestines for digestion.
Increased levels of bilirubin within the body are associated with a condition called jaundice, which occurs in toxic or infectious diseases of the liver. The most common symptom of jaundice is a yellow pigmentation of the skin.
Elevated levels of bilirubin may also arise as a result of an obstruction in the bile duct or gall bladder, as a result of haemolysis (the destruction of red blood cells), or by the liver not actively treating the haemoglobin it is receiving.
Therefore the Randox Bilirubin test is essential in the screening, monitoring and diagnosis of hepatic (liver function) disorders and jaundice in newborn babies.
Neonatal jaundice, otherwise known as hyperbilirubinemia, is extremely common in babies, because nearly every newborn develops a somewhat elevated bilirubin level during the first week of life.
Side effects may include excess sleepiness or poor feeding, but in some more extreme cases babies may experience seizures, cerebral palsy, delayed intellectual development, or physical abnormalities.
Early and accurate detection is therefore extremely important – making bilirubin testing fundamental. To ensure the precision of the bilirubin tests conducted in paediatric testing, Randox also offers Acusera Bilirubin Elevated Quality Control.
Monitoring the destruction of red blood cells with Randox G-6-PDH
Glucose-6-Phosphate Dehydrogenase (G-6-PDH) is an enzyme located on the X-chromosome, and so is found in every bodily cell as soon as a baby is born.
G-6-PDH is involved in the normal processing of carbohydrates and plays a critical role in red blood cells, protecting them from damage and destruction. Depleted levels of G-6-PDH can therefore cause red blood cells to become particularly vulnerable to haemolysis. G-6-PDH deficiency, which causes rapid heart rate, shortness of breath, excess tiredness, and mild to severe jaundice in new-borns, affects more than 400 million people globally.
During a baby’s new-born screening, a test for the G-6-PDH enzyme will be conducted to check for this deficiency disorder. Early diagnosis is imperative, as untreated haemolysis can result in haemolytic anaemia.
Genetic Disease Screening with Randox Copper
Copper is an essential mineral in human nutrition, and is mainly found in the brain, liver, kidneys, heart and skeletal muscle.
It aids in some of the key bodily functions including the production of red blood cells, the maintenance of nerve cells and the immune system, and the formation of bone and connective tissue. A deficiency in this mineral can therefore result in bone abnormalities or fractures in premature babies.
Copper deficiency can also be caused by an inherited disorder called Menkes Disease. Affecting approximately 1 in 100,000 children worldwide, this condition is characterised by sparse, kinky hair; failure to gain weight and grow at the expected rate, and deterioration of the nervous system.
The first signs of Menkes Disease – curly, sparse, coarse, dull, and discoloured hair – usually first develop at 2-3 months of age and therefore monitoring copper levels in babies is a way to catch this rare condition at the earliest possible opportunity.
Testing for Lupus with Randox Complement C4 and Complement C3
Another condition which can affect newborn babies is neonatal lupus, which occurs when the mother’s antibodies affect the foetus. A rare condition, it is an autoimmune disease caused by the body’s immune system attacking its own tissues and organs.
The Complement C4 and Complement C3 proteins, which play an important role in eliminating certain infections, can be used as biomarkers in the diagnosis and monitoring of lupus. Complement C4 deficiency is commonly associated with lupus, as the protein is required to clear damaged cells, promote inflammation, and attack pathogens.
Although there is no cure for lupus at present, the condition is very treatable and usually responds well to a number of different types of medication – especially when treatment is started in the early stages of the disease.
Early diagnosis is therefore imperative, and the Randox Complement C4 and Complement C3 tests can help to diagnose babies with lupus at the earliest possible stage. Randox also offer Acusera Immunology controls.
Monitoring a baby’s anti-infection defences with Randox IgA
IgA (immunoglobulin A) is an antibody present in the cells of the immune system, and plays a crucial role in the immune function of mucous membranes including tears, saliva, and sweat. It is also present in colostrum, often referred to as ‘liquid gold’, which is the first secretion from the mammary glands after giving birth.
It’s the IgA in colostrum and milk that is important in neonatal protection against infection and it is therefore imperative to monitor the levels of this antibody to make sure your baby is receiving the anti-infection defences he or she requires.
Testing for allergic reactions with Randox IgE
IgE (immunoglobulin E) is an antibody released by the immune system as a defence mechanism when it believes the body is at risk. IgE determinations are therefore used as an aid in the diagnosis of allergic diseases.
In babies, an allergen-specific IgE test may be done to look for some kinds of allergies, including food, animal dander, pollen, mould, medicine, dust mites, or insect venom.
Increased concentrations of IgE will confirm that an allergic response has occurred, facilitating further investigation as to the specific allergy present.
Testing for bacterial infection with Randox CRP
C-reactive protein (CRP) is an acute phase protein found in blood plasma and produced by the liver. The concentration levels of CRP increase in response to cytokines which are produced by white blood cells during inflammation, infection and tissue injury.
Testing for this protein can therefore be used in the detection of bacterial infections in neonates – enabling antibiotic prescription and a speedy recovery. If infection is identified, CRP can also be used to monitor treatment response or identify neonatal septicaemia.
Randox is committed to saving and improving lives – at any age and any stage of life.
Our innovative diagnostic technologies are versatile and easily adapted for use in the paediatric setting – keeping your baby healthy now and into the future.
In a recent article, Error Methods Are More Practical, But Uncertainty Methods May Still Be Preferred, James Westgard comments on the latest developments in the debate on the use of analytical total error (TE) and measurement uncertainty (MU), a debate which has been regularly revisited for the last twenty years. This blog aims to briefly explore the benefits of MU and TE and attempt to draw a conclusion on which is most beneficial in the clinical laboratory.
Many things can undermine a measurement. Measurements are never made under perfect conditions and in a laboratory, errors and uncertainties can come from (Good Practice Guide No. 11, 2012):
- The measuring instrument – instruments can suffer from errors including bias, changes due to ageing, wear, poor readability, and noise.
- The item being measured – the sample may be unstable.
- The measurement process – the analyte may be difficult to measure
- ‘Imported’ uncertainties – calibration of the instrument.
- User error – skill and judgement of the operator can affect the accuracy of a measurement.
- Sampling issues – the measurements you make must be properly representative of the process you are trying to assess. I.e. not using fully commutable controls will mean your quality control process is not reflective of a true patient sample.
Random and systematic errors
The effects that give rise to uncertainty in a measurement can be either random or systematic, below are some examples of these in a laboratory.
- Random – bubbles in reagent, temperature fluctuation, poor operator technique.
- Systematic – sample handling, reagent change, instrument calibration (bias), inappropriate method.
Total Error (TE) or Total Analytical Error (TAE) represents the overall error in a test result that is attributed to imprecision (%CV) and inaccuracy (%Bias), it is the combination of both random and systematic errors. The concept of error assumes that the difference between the measured result and the ‘true value’, or reference quantity value, can be calculated (Oosterhuis et al., 2017).
TE is calculated using the below formula:
TE = %BIAS + (1.96 * %CV)
Measurement Uncertainty is the margin of uncertainty, or doubt, that exists about the result of any measurement.
There is always margin of doubt associated with any measurement as well as the confidence in that doubt, which states how sure we are that the ‘true value’ is within that margin. Both the significance, or interval, and the confidence level are needed to quantify an uncertainty.
For example, a piece of string may measure 20 cm plus or minus 1 cm with a 95% confidence level, so we are 95% sure that the piece of string is between 19 cm and 21 cm in length (Good Practice Guide No. 11, 2012).
Standards such as ISO 15189 require that laboratories must determine uncertainty for each test. Measurement Uncertainty is specifically mentioned in section 184.108.40.206:
“The laboratory shall determine measurement uncertainty for each measurement procedure in the examination phases used to report measured quantity values on patients’ samples. The laboratory shall define the performance requirements for the measurement uncertainty of each measurement procedure and regularly review estimates of measurement uncertainty.”
Uncertainty is calculated using the below formula:
u = √A2+B2
U = 2 x u
A = SD of the Intra-assay precision
B = SD of the Inter-assay precision
u = Standard Uncertainty
U = Uncertainty of Measurement
Error methods, compared with uncertainty methods, offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine (Oosterhuis et al., 2018).
It is important not to confuse the terms ‘error’ and ‘uncertainty’.
- Error is the difference between the measured value and the ‘true value’.
- Uncertainty is a quantification of the doubt about the measurement result.
Whenever possible we try to correct for any known errors: for example, by applying corrections from calibration certificates. But any error whose value we do not know is a source of uncertainty (Good Practice Guide No. 11, 2012).
While Total Error methods are firmly rooted in laboratory medicine, a transition to the Measurement Uncertainty methods has taken place in other fields of metrology. TE methods are commonly intertwined with quality assurance, analytical performance specifications and Six Sigma methods. However, Total Error and Measurement Uncertainty are different but very closely related and can be complementary when evaluating measurement data.
Whether you prefer Measurement Uncertainty, Total Error, or believe that they should be used together, Randox can help. Our interlaboratory QC data management software, Acusera 24•7, automatically calculates both Total Error and Measurement Uncertainty. This makes it easier for you to meet the requirements of ISO:15189 and other regulatory bodies.
This is an example of the type of report generated by the 247 software. MU is displayed for each test and each lot of control in use therefore eliminating the need for manual calculation and multiple spreadsheets.
Fig. A and Fig. B above are examples of report generated by the 24•7 software. Fig.A shows how MU is displayed for each test and each lot of control in use therefore eliminating the need for manual calculation and multiple spreadsheets. Fig. B shows TE displayed for each test.
Acusera Third Party Controls
The Importance of ISO 15189
Good Practice Guide No. 11. (2012). Retrieved from http://publications.npl.co.uk/npl_web/pdf/mgpg11.pdf
Hill, E. (2017). Improving Laboratory Performance Through Quality Control.
Oosterhuis, W., Bayat, H., Armbruster, D., Coskun, A., Freeman, K., & Kallner, A. et al. (2017). The use of error and uncertainty methods in the medical laboratory. Clinical Chemistry and Laboratory Medicine (CCLM), 56(2). http://dx.doi.org/10.1515/cclm-2017-0341
Westgard, J. (2018). Error Methods Are More Practical, But Uncertainty Methods May Still Be Preferred. Clinical Chemistry, 64(4), 636-638. http://dx.doi.org/10.1373/clinchem.2017.284406