• Product name
    Human C Reactive Protein ELISA Kit
    See all C Reactive Protein kits
  • Detection method
  • Precision
    Sample n Mean SD CV%
    Human serum 5 1.5%
    Sample n Mean SD CV%
    Human serum 3 7.2%
  • Sample type
    Cell culture supernatant, Serum, Heparin Plasma, EDTA Plasma, Citrate Plasma
  • Assay type
    Sandwich (quantitative)
  • Sensitivity
    4 pg/ml
  • Range
    15.63 pg/ml - 1000 pg/ml
  • Recovery

    90.1 %

    Sample specific recovery
    Sample type Average % Range
    Cell culture media 90.1 88.3% - 93.4%

  • Assay time
    1h 30m
  • Assay duration
    One step assay
  • Species reactivity
    Reacts with: Human
  • Product overview

    Abcam’s C-Reactive Protein (CRP) in vitro SimpleStep ELISA® (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of CRP protein in Human cell culture supernatant, serum and plasma samples.

    The SimpleStep ELISA® employs an affinity tag labeled capture antibody and a reporter conjugated detector antibody which immunocapture the sample analyte in solution. This entire complex (capture antibody/analyte/detector antibody) is in turn immobilized via immunoaffinity of an anti-tag antibody coating the well. To perform the assay, samples or standards are added to the wells, followed by the antibody mix. After incubation, the wells are washed to remove unbound material. TMB substrate is added and during incubation is catalyzed by HRP, generating blue coloration. This reaction is then stopped by addition of Stop Solution completing any color change from blue to yellow. Signal is generated proportionally to the amount of bound analyte and the intensity is measured at 450 nm. Optionally, instead of the endpoint reading, development of TMB can be recorded kinetically at 600 nm.

  • Notes

    CRP displays several functions associated with host defense: it promotes agglutination, bacterial capsular swelling, phagocytosis and complement fixation through its calcium-dependent binding to phosphorylcholine. CRP can interact with DNA and histones and it may scavenge nuclear material released from damaged circulating cells. CRP is secreted; it forms a homopentamer pentaxin (or pentraxin) which have a discoid arrangement of 5 non-covalently bound subunits. CRP binds 2 calcium ions per subunit. The concentration of CRP in plasma increases greatly during acute phase response to tissue injury, infection or other inflammatory stimuli. It is induced by IL1/interleukin-1 and IL6//interleukin-6.

  • Tested applications
    Suitable for: Sandwich ELISAmore details
  • Platform



Our Abpromise guarantee covers the use of ab181416 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
Sandwich ELISA Use at an assay dependent concentration.


  • ELISA Protocol Summary
  • Background-subtracted data values (mean +/- SD, n=2) are graphed.

  • Background subtracted data values (mean +/- SD, n=2) are graphed.

  • 10,000X diluted sera from 10 apparently healthy male donors were measured using this kit. Interpolated data values corrected for sample dilution are graphed in ng of CRP per mL of serum (mean +/- SD, n=2). Nine out of ten individual Human sera tested within or at reported Human serum range (< 5,000 ng/mL, dotted line). The mean of CRP concentration of these nine individual sera was determined to be 2,240 ng/mL with a range of 559 – 5,285 ng/mL. Note that one individual Human serum sample (donor # 2) tested substantially higher, 11,737 ng/mL.

  • Background subtracted data values of two serum dilutions (as indicated in parenthesis) are graphed (mean +/- SD, n=2).

  • The concentrations of CRP were interpolated from data values shown above using the CRP standard curve, corrected for sample dilution, and graphed in ng of CRP per mL of serum. As expected, note that the CRP serum concentrations are increased in RA patients.



This product has been referenced in:
  • Mentoor I  et al. Metabolic syndrome and body shape predict differences in health parameters in farm working women. BMC Public Health 18:453 (2018). ELISA ; Human . Read more (PubMed: 29618342) »
  • Cartwright M  et al. A broad-spectrum infection diagnostic that detects pathogen-associated molecular patterns (PAMPs) in whole blood. EBioMedicine N/A:N/A (2016). Sandwich ELISA ; Human . Read more (PubMed: 27333027) »
See all 3 Publications for this product

Customer reviews and Q&As

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1-2 of 2 Abreviews

The focus of our lab is on quantifying concentrations of markers of human health and disease, like C-reactive protein, in dried blood spot (DBS) samples rather than serum samples due to ease of collection in the field.
We have an in-house CRP ELISA assay that takes approximately 6 hours to run from addition of sample to wells to reading the absorbance on a microplate reader. I simultaneously ran both our in-house ELISA CRP assay and the CRP Human SimpleStep ELISA on the same set of 30 DBS samples, nine DBS standards, and serum standards provided with the SimpleStep kit. For our regular CRP assay, we elute one 1/8" round punch from a larger dried blood spot on filter paper in 250 ul of phospate buffer with 0.1% TWEEN and load 100 ul per well, which corresponds to a dilution factor of approximately 167-fold. Because of the incredible sensitivity of the SimpleStep kit, I made an additional 1:100 dilution for all DBS samples for a final dilution of around 16 700. From start to finish, the Simple Step assay took about 90 minutes - the time that it took to finish the first incubation step of our inhouse assay. The instructions were extremely easy to follow, both the serum standard curve and dried blood spot standard curves had a R2 value of 1, and the sample values showed excellent correspondence with those obtained using our in-house assay (R2 = 0.95). The intra-assay CV for replicate wells was an impressive 3.21% versus the 7.9% for our in-house assay.
The only drawback of this kit is the extra time required to dilute samples down to pg/mL levels, as serial dilutions are required however, the ease of use and substantial overall time savings more than compensate for this drawback.

Dr. Geeta Eick

Verified customer

Submitted Aug 20 2014

Overall great product

Good Excellent 5/5 (Ease of Use)
This product requires half day compared to traditional one-day work for ELISA.
Pros: Quick and easy

Cons: Lower sensitivity than the traditional counterpart Abcam carries. This is not an issue for CRP since its concentration is generally high.
The amount of sample diluent is not sufficient to do an accurate dilution given that you have ~96 samples.

Abcam user community

Verified customer

Submitted Jul 02 2014

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