C-Reactive Protein

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Serum-Saliva Correlation NA
Sensitivity 10 pg/mL
Sample Test Volume 50 μL
Recommended Collection Volume 125 μL*
Special Considerations

Passive Drool is a Preferred Collection Method

CRP is Location Dependent

Collection Protocol Download PDF


  1. Ridker, P.M. (2003). Clinical application of C-reactive protein for cardiovascular disease detection and prevention. Circulation, 107(3), 363-9.
  2. Pearson, T.A., Mensah, G.A., Alexander, R.W., et al. (2003). Markers of inflammation and cardiovascular disease: Application to clinical and public health practice. A statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation,107(3), 499- 511.
  3. Buffon, A., Liuzzo, G., Biasucci, L.M., et al. (1999). Preprocedural serum levels of C-reactive protein predict early complications and late restenosis after coronary angioplasty. J Am Coll Cardiol, 34(5), 1512-21.
  4. Danesh, J., Wheeler, J.G., Hirschfield, G.M., et al. (2004). C-Reactive protein and other circulating markers of inflammation in the prediction of coronary heart disease. N Engl J Med, 350(14), 1387-97.
  5. Sesso, H.D., Buring J.E., Rifai, N., et al. (2003). C-Reactive protein and the risk of developing hypertension. JAMA, 290(22), 2945-51.
  6. Blake, G.J., Rifai, N., Buring, J.E., & Ridker, P.M. (2003). Blood pressure, C-reactive protein, and risk of future cardiovascular events. Circulation, 108(24), 2993-9.
  7. Dehghan, A., Kardys, I., de Maat, M.P., et al. (2007). Genetic variation, C-reactive protein levels, and incidence of diabetes. Diabetes, 56(3), 872-8.
  8. Pradhan, A.D., Manson, J.E., Rifai, N., et al. (2001). C-reactive protein, interleukin 6, and risk of developing type 2 diabetes mellitus. JAMA, 286(3), 327-34.
  9. Du Clos, T.W. Editorial: C-reactive protein as a regulator of autoimmunity and inflammation. (2003). Arthritis Rheum, 48(6), 1475-77.
  10. Krasteva, A., Perenovska, P., Ivanova, A., et al. (2010).  Alteration in salivary components of children with allergic asthma.  Biotechnology Biotehnological Equipment, 24(2), 1866-69.
  11. Gutiérrez, A.M., Martínez-Subiela, S., Soler, L., et al. (2009).  Use of saliva for haptoglobin and C-reactive protein quantifications in porcine respiratory and reproductive syndrome affected pigs in field conditions.  Vet Immunol Immunopathol, 132(2-4), 218-23.
  12. Salimetrics internal data.
  13. Giannobile, W.V., Beikler, T., Kinney, J.S., et al. (2009). Saliva as a diagnostic tool for periodontal disease: Current state and future directions.  Periodontol 2000, 50, 52-64.
  14. Higashi, Y., Goto, C., Jitsuiki, D., et al. (2008).  Periodontal infection is associated with endothelial dysfunction in healthy subjects and hypertensive patients.  Hypertension, 51(2), 446-53.
  15. Miller, C.S., Foley, J.D., Bailey, A.L., et al. (2010).  Current developments in salivary diagnostics.  Biomark Med, 4(1), 171-89.
  16. Floriano, P.N., Christodoulides, N., Miller, C.S., et al. (2009). Use of saliva-based nano-biochip tests for acute myodardial infarction at the point of care: A feasibility study.  Clin Chem, 55(8), 1530-38.
  17. Gómez-Laguna, J. Gutiérrez, A., Pallarés, F.J., et al. (2010). Haptoglobin and C-reactive protein as biomarkers in the serum, saliva and meat juice of pigs experimentally infected with porcine reproductive and respiratory syndrome virus.  Vet J, 185(1), 83-7.
  18. Gutiérrez, A.M., Martínez-Subiela, S., Eckersall, P.D., Cerón, J.J. (2008). C-reactive protein quantification in porcine saliva: A minimally invasive test for pig health monitoring.  Vet J, 181(3), 261-5.
  19. Tonetti, M.S., D’Aiuto, F., Nibali, L., et al. (2007). Treatment of periodontitis and endothelial function. N Engl J Med, 356(9), 911-20.
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​The effects of freeze thaw on most biological measures, regardless of biospecimen type, can be dramatic. Analytes in oral fluid are not distinct or different in this way. As a general rule, multiple freeze-thaws should be avoided.  The most practical way to address this concern is by aliqouting samples after collection. Some analytes are more resistant to freeze thaw than others. We recommend that investigators consult the literature for the analytes of interest. If there is freeze thaw data for a specific biological measure in traditional biospecimens, it is reasonable to assume this would also be true for saliva.


​No, but the literature is rather extensive on this subject for several salivary analytes; especially for salivary alpha-amylase and cortisol. We do not track that information internally. 


​With modern search tools online, we no longer maintain records of this type. We suggest that you use Pubmed or Psychlit to search the literature or you can Ask An Expert and we will be happy to assist you in your search.


​If the analyte you are interested in is not noted in our website, please contact Dr. Granger at [email protected] to find out what developments are in the pipeline.


​Salimetrics does not release products for sale if the quality control (QC) testing shows any issues. Here are some probable causes:

1) Can timing of adding reagents be off?  For instance with a multichannel you can pipette the conjugate and TMB so many times before you refill, but you can pipette the stop twice as fast because it is a smaller volume.  If you do this, it shortens the time the bottom rows have with TMB.

2) Can your washer be uneven and sheering off antibody in the bottom corner?  Aspirate and check the amount of fluid left.  It should be even in all wells and no wells should be completely dry.

3) Are you mixing faster than recommended?  Or slower?  

4) Are all reagents completely at room temperature?  A bottle of assay diluent takes 2 hours to come to RT.  You can pour some off into a smaller tube to warm up quicker for the zero and nsb.

5) Are you leaving the plate come to room temperature BEFORE opening the bag? (Otherwise moisture due to humidity may form in the wells and this is particularly a problem in this high humidity weather)

6) Are your multichannel pipettes dispensing the same amount each time reliably?  We discard the first and last dispenses as they are not as reliable.

7) Are you incubating with TMB in the dark?  (We no longer recommend aluminum foil.)

8) Are you testing one plate at a time?  For example, do not put the standards on 5 plates then go back and fill in with samples. This delays the addition of conjugate to the plates.

9) Clean your plate reader filter. Dust from the lab can collect on the filter.

10) Are you adding assay diluent to the zero in sequence after the standards and not the last thing?

11) Never put the multichannel pipette tips into the wells as you can drag down standard from the wells above it causing lower readings in other wells.

12) Thoroughly blot all wells just before adding TMB but do not let the plate dry out.