Calprotectin in Serum

Calprotectin in Serum

Calprotectin is a soluble protein that is found in white cells; it is part of the bodies defence mechanism and has strong antibacterial and antifungal properties through its ability to sequester metal ions. Calprotectin is actually formed from two proteins, S100-A8 and S100-A9 (alternatively known as MRP-8 and MRP-9) and it is the heterodimer of these two proteins that is found inside the white cells. When calprotectin is released from white cells, it initiates a strong inflammatory response and rapidly forms a tetrameric format in conjunction with metal ions (calcium, zinc, magnesium).

There is as much calprotectin in white cells as there is haemoglobin in red cells accounting for around 60% of the soluble protein content. In conditions which provoke an inflammatory response the level of calprotectin in the blood can increase significantly and although it is a non-specific marker, it can be used to aide diagnosis and determine the severity of certain conditions in conjunction with the other clinical evidence. The diagnostic advantage of calprotectin detection over other disease markers is that it is stored in the cell and released immediately in response to local situations. In contrast, other markers may be released by downstream pathways or need to be synthesised leading to delays in detection.

Although calprotectin is a non-specific marker, there have been publications to show it to be of value in the diagnosis and monitoring of various conditions including:

  • Rheumatoid and juvenile idiopathic arthritis
  • An early marker for sepsis
  • An early marker for acute coronary syndromes
  • Idiopathic pulmonary fibrosis
  • Behcet’s disease
  • Stills disease
  • Systemic lupus erythematosus
  • Systemic sclerosis
  • Primary Sjorgens Syndrome

Quantum Blue® sCAL

The Quantum blue test system combines the ease and speed of lateral flow technology (a bit like a COVID or pregnancy test device) with full quantitation by means of a small bench top reading device:(BI-POCTR-ABS3).

The system can be used in the laboratory if the volume of tests isn’t too high, or it can be used in clinics as a point of care option. The assay detects the dimeric format of serum calprotectin. There are 25 tests in each kit and all are individually sealed so you can use them one at a time if required. Results are available in 12 minutes.

  • Assay range: 0.42 – 10µg/ml
  • Assay time: 12 minutes
  • Sample type: Serum
  • Sample volume required: 20µl

Buy Online

Serum Calprotectin Quantitative Lateral-flow Test
Product Code Description Pack Size
LF-MRP25 Quantum Blue® sCAL 25 Tests

Key Literature

Quantum Blue Brochure


• Simple Blood Test Could Transform Covid Patient Care
A simple test to identify patients at increased risk of death from Covid-19 could be a step closer thanks to a funding grant made by the University of Dundee, with the use of Quantum Blue® sCAL (LF-MRP25).

• Supporting POC diagnosis of Peritonsilar Abscess
The QUANTUM BLUE sCAL Test (QBT) is an appropriate POCT to determine serum and salivary calprotectin levels. Thus, PTA scores can be determined within a short time frame by applying the QBT during outpatient management.

• 21 Park et al: MRP8/14 serum levels as diagnostic markers for systemic juvenile idiopathic arthritis in children with prolonged fever. Rheumatology 2021; 00: 1-11
“Rapid results may enable effective treatment within a window of opportunity preventing disease progression” (sensitivity 84%, specificity 81%):

Click here to read the Publications relating to Calprotectin Serum


The sCAL ELISA is a micro-titre based assay kit for determination of the dimeric format of calprotectin in serum samples. All reagents, standards and controls are provided in one kit and are in a ready to use format. There is no requirement for reconstituting any component, apart from the wash buffer so this minimises any errors and ensures a long shelf life. The ELISA can be performed manually or on a DS2 automated processor to reduce hands–on time in higher throughput environments.

  • Assay range: 0.42 – 24µg/ml
  • Assay time: 75 minutes
  • Sample type: Serum
    • Note: measurement in plasma from heparinized or citrated blood samples is possible, but be aware that normal values are slightly effected by the sample type used.

Buy Online

Serum Calprotectin Quantitative Lateral-flow Test
Product Code Description Pack Size
EK-MRP8/14 MRP8/14 ELISA 96 well plate


• Helping to Manage Juvenile Idiopathic Arthritis
Great Ormond Street Hospital User Report – Serum Calprotectin Monitoring

•  To establish a test for MRP8/14 protein in childhood arthritis
Ahmed et al. Great Ormond Street Hospital

• Hurnakova: Serum calprotectin discriminates subclinical disease activity from ultra-sound defined remission in patients with RA in clinical remission
Shows the “potential ability of serum calprotectin to discriminate ultrasound-defined remission from subclinical disease activity in RA patients who have achieved clinical remission. Overall, this study suggests that calprotectin might represent a valuable serological biomarker for confirming deep remission in RA patients”

• 21 Park et al: MRP8/14 serum levels as diagnostic markers for systemic juvenile idiopathic arthritis in children with prolonged fever. Rheumatology 2021; 00: 1-11
“Rapid results may enable effective treatment within a window of opportunity preventing disease progression” (sensitivity 84%, specificity 81%):

• Ma et al: Serum Calprotectin Can Differentiate Between Sustained Remission and Low Disease Activity States in Rheumatoid Arthritis. ACR Paediatric Rheumatology symposium
This study demonstrated the role of calprotectin in differentiating subtle low disease activity states. Serum calprotectin was significantly different between low disease activity and remission as defined using different remission criteria. Its utility was seen with point remission as well as longitudinally over 1 year.

• La et al: Serum calprotectin (S100A8/A9): a promising biomarker in diagnosis and follow-up in different subgroups of juvenile idiopathic arthritis
This study confirms the interest of sCal as a potential marker of response to treatment or risk of flares. It also highlights its role as a useful diagnostic tool and marker of disease activity, with a greater specificity than with C-reactive protein.

• Marushko et al: Evaluation of serum calprotectin (MRP-8/MRP-14) levels in patients with juvenile idiopathic arthritis
sCal levels should be used to monitor the subclinical inflammatory activity in patients with JIA.

Click here to read the Publications relating to Calprotectin Serum

sCAL turbo

The BÜHLMANN sCAL® turbo is an in vitro diagnostic test designed for the quantitative determination of the tetrameric format of calprotectin (MRP8/14) in human serum samples to avoid the background calprotectin that will be found in standard blood samples. This is the dominant format found in serum due to the high and even distribution of calcium.

The BÜHLMANN sCAL® turbo test is a particle enhanced turbidimetric immunoassay (PETIA) and allows quantification of calprotectin in human serum samples on clinical chemistry analysers. Samples can be measured without any additional dilution steps and are incubated with reaction buffer and mixed with polystyrene nanoparticles coated with calprotectin-specific antibodies (immunoparticles). Any calprotectin available in the sample mediates immunoparticle agglutination and sample turbidity which is measured by light absorbance. The detected light absorbance allows quantification of calprotectin concentration via interpolation on an established calibration curve.

Assay Details:

  • Sample volume: ~2-3µl
  • Time to first result: 10 minutes
  • Assay Range: 0.23 – 15µg/ml but can dilute 1:15 to cover 15 – 225µg/ml
  • Number of tests: Approximately 100 (dependent on the platform used)
  • All reagents are ready to use and have an on-board stability of 55 days
  • Calibration is stable for at least 30 days, but is analyser dependant
  • Accuracy/Recovery: 92 – 112.8%
  • Limit of Detection: 0.11µg/ml
  • Limit of Quantification: 0.23µg/ml

There is excellent correlation to other turbidimetric assays that are available:

Assay standardisation:

The BÜHLMANN sCAL® turbo is standardized against internal reference material (purified native calprotectin). Calibrator and control values are assigned according to a value transfer protocol (ref. 1, 2), to guarantee metrological traceability. The analytical measuring interval of the BÜHLMANN sCAL® turbo, established on the Mindray BS-480 instrument, is 0.23-15.0 μg/mL.

Sample Collection:

Blood can be collected into a serum tube or a gel separator tube, once clotted the tubes are centrifuged at 1800g for 15 minutes and then the serum transferred into a plain tube. This then prevents the contamination of the sample with un-released calprotectin which would cause higher values. Once separated the samples can be stored at 2-8C for 16 days or for 1 month at -20C.

Reference Interval:

The reference interval of the BÜHLMANN sCAL® turbo assay was established according to CLSI C28-A3 with 160 serum samples from self-declared healthy individuals: adult men and women aged 18 to 83 years. The samples were collected either in native tube or tube with gel separator and processed within 3-4 hours after collection.

Comparison of the BUHLMANN sCAL ELISA to the sCAL turbo:

Because the assays are manufactured by the same company they have a good correlation, however they are based on different standardisations and so will give significantly different results. The sCAL ELISA is based on the historic use of the dimeric format which will include the background level found normally within blood.

The sCAL turbo is based on the tetrameric format which avoids the background level and so lower values will be obtained.

Buy Online

Serum Calprotectin Immuno Turbidimetric Reagent
Product Code Description Pack Size
KK-SCAL sCAL® turbo 100 tests

• A novel Serum Calprotectin (MRP8/14) particle enhanced immuno-turbidimetric assay (sCAL turbo) helps to differentiate SJIA from other diseases in routine clinical laboratory settings
The sCAL turbo assay showed an excellent correlation to the MRP8/14 ELISA used in the previous validation studies (r=0.99, p<0.001). It could reliably differentiate SJIA from all other diagnoses with significant accuracy (cut-off at 9,100 ng/ml, sensitivity 93%, specificity 87%, ROC area under curve 0.961 p<0.001).

Click here to read the Publications relating to Calprotectin Serum