The D-Dimer test is a crucial diagnostic tool in haemostasis testing, widely used for the exclusion of deep vein thrombosis (DVT) and pulmonary embolism (PE). It plays a vital role in identifying conditions related to excessive clot formation and fibrinolysis, offering clinicians an effective means to rule out serious thrombotic disorders.
This article explores the importance of the D-Dimer test, its diagnostic value, and how advanced reagents like Operon Biotech’s FibriLine D-Dimer improve accuracy and efficiency in clinical settings.
During blood coagulation, fibrinogen is converted into fibrin via thrombin activation. The fibrin forms a clot, stabilized by Factor XIII, creating an insoluble fibrin mesh. When the clot begins to degrade, the enzyme plasmin breaks down cross-linked fibrin, releasing D-Dimer fragments, which serve as biomarkers of clot formation and dissolution.
D-Dimer levels are thus an indicator of active thrombosis and fibrinolysis, making this test essential for diagnosing and monitoring coagulation disorders.
The D-Dimer assay is widely used to assess thrombotic conditions such as:
D-Dimer testing has a high negative predictive value (>95%), meaning a negative result effectively rules out thrombosis. However, due to low specificity, elevated D-Dimer levels may also be seen in conditions such as pregnancy, infections, cancer, and inflammation, necessitating further clinical correlation.
Studies show that combining the Wells Score (a clinical prediction tool) with D-Dimer testing improves diagnostic accuracy. In patients with a low Wells score and a negative D-Dimer result, DVT can be safely ruled out without further imaging.
Meta-analyses indicate that D-Dimer testing is more sensitive for proximal DVT than distal DVT. For suspected isolated distal deep vein thrombosis (IDDVT), D-Dimer alone may not be sufficient, and additional imaging is often required. The predictive negative value for IDDVT diagnosis varies, with some studies reporting <90%, while others suggest ≥97%.
The FibriLine D-Dimer reagent by Operon Biotech & Healthcare is a clinically proven, high-quality reagent designed for rapid and reliable DVT and PE exclusion. It is compatible with Operon’s automated coagulation analyzers (XL-1000C, XL-1000i, and XL-1000e), offering:
The Operon FibriLine D-Dimer Latex is a rapid agglutination assay utilizing latex beads coupled with a highly specific D-Dimer monoclonal antibody. Cross-linked fibrin degradation products (XL-FDP) in a plasma sample bind to the coated latex beads, causing visible agglutination when D-Dimer concentration surpasses the assay’s detection threshold.
The FibriLine D-Dimer kit includes:
A FibriLine D-Dimer calibrator is used for automated 5-dilution calibration Log-Log curve on Operon XL-1000 series instruments. Once calibrated, sample processing is as simple as performing a PT test. The system automates dilution, runs the assay, and provides a quantitative result in ~5 minutes, ensuring high reliability and accuracy. To further enhance confidence in reporting, running quality controls with every batch is recommended.
FibriLine D-Dimer testing is fully automated on the XL-1000 series coagulation analyzers, ensuring:
This automation minimizes human error, ensuring high reliability and reproducibility in thrombosis screening and exclusion testing.
The D-Dimer test is an indispensable tool in diagnosing and managing thrombotic conditions. When combined with clinical prediction models like the Wells Score, it enhances diagnostic accuracy, reducing unnecessary imaging.
However, D-Dimer alone does not exclude the presence of IDDVT in patients with a time of ≥4 days between symptom onset and testing. In moderate-risk patients, the negative predictive value may be lower, and further studies are needed to determine its diagnostic efficacy.
FibriLine D-Dimer by Operon Biotech provides a highly sensitive, reliable, and automated solution for laboratories, improving workflow efficiency and ensuring high-quality patient care.
For clinical laboratories aiming for efficiency, precision, and cost-effectiveness, adopting advanced D-Dimer testing solutions is a step toward better diagnostic outcomes and improved patient management.
About Operon Biotech: Operon Biotech and Healthcare is a professionally managed biomedical company dealing with quality Coagulation product ranges. With a market presence and expertise in coagulation devices. You can reach out to Operon Biotech team at info@operonbiotech.com or on +91-9008178817.
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In modern healthcare, automated coagulation analyzers are transforming blood clot management by providing highly accurate, rapid, and efficient diagnostics. These devices play a pivotal role in diagnosing and managing bleeding disorders, thrombosis, and anticoagulation therapy—ensuring timely treatment and improved patient outcomes.
Coagulation testing assesses the blood’s ability to clot, aiding in the diagnosis and monitoring of various conditions, such as:
Modern coagulation analyzers process large sample volumes with minimal manual intervention, ensuring efficiency and accuracy in high-throughput labs.
Advanced devices conduct a range of coagulation tests, including:
Innovative analyzers, like FibriTimer Zeta-1, incorporate mechanical and optical clot detection. This dual technology enhances test accuracy, minimizes false readings, and ensures reliable results even with challenging samples (e.g., turbid or hemolyzed specimens).
Modern analyzers feature intuitive touchscreen interfaces, LIS connectivity, and remote access capabilities for seamless lab integration and efficient data management.
Automated analyzers adhere to strict quality control protocols, utilizing built-in Westgard rules and real-time monitoring to ensure consistent and reproducible results.
Healthcare facilities, ranging from small clinics to large hospitals, require accurate and timely coagulation reports for pre-surgical screening, emergency management, and chronic disease monitoring. High-performance analyzers provide the reliability needed for critical patient care.
When selecting a coagulation analyzer, consider:
Emerging trends in coagulation diagnostics include:
Operon Biotech has earned a strong reputation in coagulation diagnostics by offering high-quality, innovative, and cost-effective solutions. With years of industry expertise, the company delivers:
Automated coagulation analyzers are redefining hematology diagnostics, offering unmatched precision, efficiency, and speed. Whether for high-throughput hospital labs or mid-sized clinical settings, investing in a cutting-edge coagulation testing system ensures better patient outcomes, reduced errors, and cost-effective operations.
With FibriTimer Zeta-1, healthcare providers gain access to patented dual technology, ensuring fast, accurate, and reliable results—paving the way for the future of precision blood clot management.
For more insights into the latest coagulation advancements, Reach out to Operon Biotech team at info@operonbiotech.com
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Questions/ Feedback? We’d love to hear from you! Feel free to write to us on info@dfinebio.in or comment in the section below.
Coagulation reagents are among the most important reagents applied in clinical laboratories for evaluating defects in bleeding and thrombotic functions. They enable proper assessment of clotting disorders, which in turn help clinicians in the diagnosis and treatment of events like or related to haemophilia, thrombosis, or liver diseases. They thus form an important aspect of healthcare delivery and ensuring accurate patient care.
The choice of suitable reagents with adequate quality is a prerequisite for the generation of accurate and reliable results from laboratory testing. However, there are no universal guidelines regarding the selection process, and each laboratory or institution develops their own standards and procedures for their choice of reagents. In addition, it may be challenging to evaluate the numerous available products from various manufacturers
At Operon Biotech and Healthcare we understand such intricacies a lab faces while choosing a right reagent or instrument for its lab. In another article, I have extensively covered on how to choose the right coagulation analyzer for your lab and what factors should be considered. You may want to review this article here.
This article will exclusively dwell on the right choice of reagents a lab needs to adapt. Also included is a link to a small presentation that talks on practical approach to haemostasis testing in a clinical lab with much deliberations on mixing and inhibitor studies.
First consideration in deciding for reagents should be the right vendor instead of the reagent itself. A vendor who knows coagulation as a core subject/business rather than just a add on to his other non-coagulation business. The vendor should demonstrate his acumen, knowledge and know – how in the subject of haemostasis with corporate, mid size and small labs as his serving customers. He should have a market standing with a considerable client base using his/her coagulation services. This must a non-negotiable factor for the customer. Many big names in IVD business including that in chemistry, haematology and or immunology etc have few hand-picked products in coagulation just to complete their product portfolio and such vendors should be rejected for many reasons majorly being lack of product and subject knowledge and extremely poor after sales support.
Second major should be the right selection of reagents. Here are few tips:
PT reagent choice:
Important tip/s: Keep the unused reagents back in refrigerator and for testing transfer a well-mixed PT reagent in a smaller container that can be refilled from refrigerated stock as required. This will give a longer shelf life to reagents. Alw keep the regents capped to avoid evaporation.
APTT reagent choice:
Important tip/s: Use only the company recommended calcium chloride for test activation. Do not use market available cacl2 as the molarity may not be the same as company recommended.
Mix the aptt reagent well before adding to sample. Do not separately incubate the aptt reagent. Just pre-warm the cacl2.
Maintain consistent incubation times and test protocols for satisfactory results.
Meanwhile, as promised do find a presentation on practical approach to haemostasis testing. Coagulation testing – a practical approach.pdf
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Questions/ Feedback? We’d love to hear from you! Feel free to write to us on info@dfinebio.in or comment in the section below.
Haemostasis – Background
Hemostasis is a collective term used to describe the body’s defence mechanism to prevent blood loss and finally dissolve the clot all via combination of multiple complex physiological process coming together. This fine balance of haemorrhage and thrombosis is termed as hemostasis and any imbalance in either or both can a fatal to patient’s life. The reasons for any imbalance in normal hemostasis could by “Provoked” like a Major surgery or an active cancer or liver disease but most reasons are Unprovoked (Hereditary).
Need for Haemostasis testing:
To understand the underlying reasons for the defects in hemostasis that could cause bleeding or thrombosis, a sequential workup is required backed with quality coagulation (Hemostasis) reports for prognosis, prophylaxis and management of patient’s health. Almost all specialities in medical profession need quality results in coagulation, thus clinicians frequently order coagulation tests for their patients for general health understanding to pre-operative and post-operative decisions.
The science behind haemostasis testing
Thrombosis and hemostasis testing is the IN-VITRO study of the ability of the blood to form clots and to break clots IN-VIVO. As thrombotic and hemostasis pathways form a part of critical disease state ranging from haemophilia to strokes and heart attacks, the testing of patient’s capabilities in thrombosis and hemostasis is a critical diagnostic tool. Should a patient’s ability to form clots in-vitro fall outside of the established norm or should certain markers be out of the normal range, the plasma sample is further assayed to determine the reason for the problem. These assays are in standard use in all hospital laboratories. The coagulation analyser’s primary usefulness is to remove the selectiveness in determining the exact second a clot forms in a sample in-vitro.
Coagulometers
Coagulometers (automated coagulation instruments) used in clinical laboratories have become increasingly complex, and the evaluation of such instruments is complicated and time consuming. The criteria in selecting a coagulation system for a laboratory that is large, processing more samples per day for both routine to speciality assays could be very different vis a vis a medium to small size lab where flow of samples per day are quiet predictable and low. Irrespective of the size of the laboratory the general guidelines for a clinical laboratory while selecting a right coagulation system could be derived from instruments assessment of safety, carryover, precision, bias, linearity, testing capabilities and correlation. Choosing a right vendor is also a significant criterion.
POCT Devices
Unlike the coagulation devices used in the lab that uses plasma as the sample, the POCT devices use whole blood. The POC devices are not a perfect product for laboratory use however they are really handy and often reliable when it comes to home use cases for patients on OAT (oral anticoagulation therapy) to monitor their INR values with a simple finger prick drop of blood being applied on a cartridge and results being read on the POC device within minutes. There also are professional use case models extending the parameters from the regular PT INR to APTT, FIB and TT on a simple whole blood. The qLabs from Micropoint marketed in India by Operon biotech is a perfect example of both personal POC device and as well as professional use POC
Current trends in automated coagulometers:
Coagulation analysers are now marketed as a “system” or “package” and include a set of recommended reagents, tailored for that particular instrument is now in commonplace. Consequently, the evaluation of coagulometers alone has become increasingly difficult and also irrelevant to the situation in most routine laboratories as its always the combination of Instrument and reagent system. These are marketed as a package and not just as stand alone with flexible ownership and buyback/upgrade options.
Current trends in semi-automated coagulometers:
Unlike the automated coagulation analysers which are mostly sorted, structured and packaged along with well-defined reagents/controls/consumables and offered in flexible ownership options including reagent rental, partial rental schemes, part payment basis the semi-automated systems are largely open type. The semi-automated systems are available as stand-alone for purchases with no clear mandate or binding on reagent use. User opts for best available reagent and consumable brands suitable for his lab ranging from small pack reagents to liquid stable. Internal quality control use among semi-automated users is a rare thing to find. There also is a lack of subject knowledge among these user group and clear absence of standardisations is a general finding. Tests barely go beyond PT and aPTT in this kind of setup.
Levels of Coagulation Automation
| Level | Description | Examples |
|---|---|---|
| The testing includes manual operations and the measurements are visual. While the temperature is maintained by water bath or heat block the end point is determined visually by the technician. Timer is initiated and stopped also by the technician. | Tilt Tube method | |
| Semiautomated | The testing includes manual operations and the measurements are automated. The semi auto device maintains the temperature on its own and the technician manually dispenses the sample/reagent at appropriate times after which the instrument reads the end point and displays the results | Fibritimer Zeta -1 Fibritimer Zeta – 2 |
| Automated | All reagents and samples are automatically pipetted by the analyzer instrument. Analyzer contains monitoring devices and internal mechanism to maintain and monitor constant 37° C temperature throughout testing sequence. Timers are initiated and clot formation is detected automatically. | Operon XL – 1000 C Operon XL-1000e |
MECHANICAL METHOD
Mechanical measurement methods depend on the detection of the physical formation of fibrin strands that stops a moving mechanical device that ultimately either completes or opens an electrical circuit.
Any test that has fibrin formation as its end point can be determined using the Mechanical Method. The Zeta-1 uses Custom made unique design cuvette with curvy-linear path at the base and a stainless-steel ball inside the cuvette.
A periodic magnetic field imparts a sustained pendular motion along a curvilinear path to the stainless-steel ball within the inner perimeter at the bottom portion of the cuvette.
The ball deflects on the curvilinear path, moving each time Left and Right in the track in a pendular motion. The ball movement is continuously monitored. The instrument registers any change in the ball’s movement caused due to change in turbidity/viscosity of the test solution and reads it as a fibrin clot. The results are generally displayed in Seconds.
At the start of coagulation, the fibrin filaments will impede the movement of the ball. thereby changing the deflection frequency of the ball’s movement. A sensor registers these changes, automatically stopping the time measurement when the ball ceases to move completely.
Photo-optical (turbidometric)
Optical method is LED assisted focusing of the light on the “test solution” wherein the desired wave length is beamed and on the other side the light passed through the “test solution” is captured through the optical receivers. Basic setup is as shown below.Effectively the amount of light received by optical receivers is not the same as the incident light and that change is indicative of the current coagulation state of the “test solution”.
Below is the graph depicting TIME Vs ABSORBANCE CHANGE
As expected, the intensity of light received at the optical receiver is decreased based on the chemical reaction/turbidity developed and instrument reads the final value.
This phenomenon is used to find the rate at which the intensity decreases.
The algorithm in the microcontroller determines the slope and finds out the “bell curve” as represented above. With this, the left point of the bell curve and right point of the bell curve are determined – with 70% of the maximum slope. Average of this left (T1) and right (T2) values are calculated and that would indicate the coagulation time
• Nephelometric
Nephelometry is a modification of photo-optical end-point detection in which 90-degree or forward-angle scatter, rather than OD, is measured. A light-emitting diode produces incident light at approximately 600 nm and a photodetector detects variations in light scatter at 90 degrees (side scatter) and at near 180 degrees (forward-angle scatter). As fibrin polymers form, side scatter and forward-angle scatter rise (Figure 47-3).4,5 The timer stops when scatter reaches a predetermined intensity, and the interval is recorded.
• Chromogenic (amidolytic)
Chromogenic (synthetic, amidolytic) methodology employs a colourless synthetic oligopeptide substrate conjugated to a chromophore, usually para-nitroaniline (pNA). Chromogenic analysis is a means for measuring specific antigen activity. The oligopeptide is a series of amino acids whose sequence matches the natural substrate of the protease being measured.7 Protease cleaves the chromogenic substrate at the site binding the oligopeptide to the pNA, freeing the pNA. Free pNA is yellow; the OD of the solution is proportional to protease activity and is measured by a photodetector at 405 nm. In some instances, a fluorescent conjugate is used; this method is called fluorogenic.
Immunologic
Immunologic assays are the newest assays available in coagulation laboratories and are based on antigen-antibody reactions similar to those used in nephelometry as described previously. Latex microparticles are coated with antibodies directed against the selected analyte (antigen). Monochromatic light passes through the suspension of latex microparticles. When the wavelength is greater than the diameter of the particles, only a small amount of light is absorbed.8 When the coated latex microparticles come into contact with their antigen, however, the antigen attaches to the antibody and forms “bridges,” which causes the particles to agglutinate. As the diameter of the agglutinates increases to the wavelength of the monochromatic light beam, light is absorbed. The increase in light absorbance is proportional to the size of the agglutinates, which in turn is proportional to the antigen level.
Final thoughts
The introduction of new coagulation methodologies has improved testing capabilities and in expanding the test menu. in the coagulation laboratory. There still is a need for further advancements wherein platelet studies, whole blood coagulation studies also if could be merged alongside the conventional plasma coagulation testing thus bringing a better understanding on defects related to hemostasis. While the systems and process are getting more and more automated and getting smarter by the day… the diminishing knowledge and failing acumen among the users on the fundamentals of testing, procedures, results interpretation is a big big cause of worry. As long the systems are functioning the results seem to be in safe hands of technology and once something goes wrong with the technology of systems and automated processes that’s where the danger zone is.
Advances in Coagulometry
Significant advances have been made in the capability and flexibility of coagulation instrumentation. Instruments previously required manual pipetting, recording, and calculation of results, which necessitated significant operator expertise, intervention, and time. Current technology allows a “walkaway” environment in which, after specimens and reagents are loaded and the AI – assisted testing sequence is initiated making the whole testing and reporting easy and seamless.
References: oncohema key, Dacie&Lewis, National Insititute of Health
Questions/ Feedback? We’d love to hear from you! Feel free to write to us on info@operonbiotech.com or comment in the section below.
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To boost up the Team spirit and as a part of refreshment, a tour was organised from 10th September to 12th September 2022 at Rosetta Ferns, Sakleshpura. Activities were the major part of this tour so as to help our organization engage with the community and colleagues.
Recreation, Entertainment & Games was arranged between the Team to build strong fellowship among us. This positive synergy enabled our Team members to be their full selves and enjoy.
Medical Fair India is a 3-day event being held from 20th May to 22nd May 2022 in Mumbai, India. It is India’s No. 1 trade fair and exhibition for health centres, clinic and hospitals.
Operon Biotech and Healthcare as a successful exhibitors as well as visitor participated to directly connect and interact with various suppliers, reputed customers of healthcare industry to grab an opportunity and enhance the business in the global market.
Medical Fair India is a 3-day event being held from 21st February to 23rd February 2019 in New Delhi, India.
Operon Biotech and Healthcare emerged as successful exhibitor in this fair and and met various suppliers and received good enquiries and response from various reputed customers of healthcare industry.
Medicall, is India’s largest B2B Medical Equipment Exhibition, in South India. Medicall provides a beneficial experience for all dealers, distributors, importers and exporters who are looking to connect with key industry players, sales and business development professionals who are tasked with expanding their product portfolios and entrepreneurs hoping to source the next ‘big product’ to supply in their country.
Operon Biotech and Healthcare participated and showcased its different Coagulation Analyzers and point of care testing devcies and received a great response from visitors .
Medical Fair India 2017 is a platform for the decision-makers and aspirants both to come forth and have open discussions on the ever growing medical engineering field in past few years. This one stop exhibition has been trending amongst its contemporaries for the ever growing demand of the field in Indian markets that refuses to cease.
Operon Biotech and Healthcare emerged as successful exhibitor in this fair and has received good number of response from Doctors Medical Practioners dealers and various other reputed healthcare customers’ worldwide.
MEDICAL FAIR INDIA is India’s no. 1 exhibition and conference for healthcare, which act as a platform where connections are made and business relationships are nurtured.
With participation from all over India and other countries Operon Biotech and Healthcare also participated and showcased it’s wide range of Invitro Diagnostic products in healthcare and point of care testing.
We were delighted to have received a great interest in our products from the visitors
