C-反應蛋白（CRP）是由於感染或其他醫療條件（例如類風濕性關節炎或狼瘡）而引起的炎症的生物標誌物。因為持續低水平的炎症也可能與心血管疾病相關，所以可以檢測血清中低水平CRP的高敏CRP（hs-CRP）檢測可用於預測心臟疾病與其他緩解因素相結合的風險。在健康的個體中，CRP的含量低於1毫克/升（mg / L）。最近的證據表明，1 mg / L至3 mg / L的CRP水平表示心血管疾病的中等風險，而大於3 mg / L的水平表示高風險。 NIST團隊生產純CRP標準參考材料，旨在校準診斷工具和程序，以更高的準確度，精確度和對國際單位制（SI）的可追溯性來衡量這些低水平的CRP。一個SRM單元包含3個小瓶，每個小瓶含有1mL含有20mmol / L TRIS-HCl（pH7.5），140mmol / L NaCl，2mmol / L CaCl 2和體積分數的含水緩衝液中的重組CRP溶液的0.05％NaN 3。報告CRP的認證濃度值以及參考密度，相對平均質量和濃度值（以每升的克數表示）。通過涉及同位素稀釋液相色譜 - 串聯質譜（ID-LC-MS / MS）的氨基酸分析，SRM 2924被認證為濃縮。這種先進的測量方法經過優化，並經過日本國家計量研究院針對CRP現有的高濃度認證參考材料進行了嚴格測試。還通過色譜和質譜技術仔細評估了SRM的穩定性。 SRS 2924由NIST開發，用於滿足體外診斷和研究界對“高階”參考材料的需求，以獲得對SI單位的可追溯性。 SRM儲存並冷凍運輸，使用前必須在室溫下解凍。
C-reactive protein (CRP) is a biomarker for inflammation due to infections or other medical conditions (e.g. rheumatoid arthritis or lupus). Because persistent low levels of inflammation can also be associated with cardiovascular disease, high-sensitivity CRP (hs-CRP) assays that can detect low levels of CRP in serum are used to predict risk of heart disease combined with other mitigating factors. In a healthy individual, CRP is found at a level less than 1 milligram per liter (mg/L) in serum. Recent evidence suggests that a CRP level between 1 mg/L and 3 mg/L indicates a moderate risk of cardiovascular disease while a level greater than 3 mg/L predicts a high risk. The NIST team produced the certified reference material of pure CRP for the intended purpose of calibrating diagnostic tools and procedures that measure these low levels of CRP with greater accuracy, precision and traceability to the International System of Units (SI). A unit of the SRM contains 3 vials, each with 1 mL of a solution of recombinant CRP in aqueous buffer containing 20 mmol/L TRIS-HCl (pH 7.5), 140 mmol/L NaCl, 2 mmol/L CaCl2 and a volume fraction of 0.05 % NaN3. A certified concentration value for CRP is reported along with reference density, relative average mass and concentration values (expressed in terms of grams per liter). SRM 2924 was certified for concentration by amino acid analysis involving isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). This advanced measurement method was optimized and rigorously tested against an existing higher-concentration certified reference material for CRP from the National Metrology Institute of Japan. Stability of the SRM was also carefully assessed through chromatographic and mass spectrometric techniques. SRM 2924 was developed by NIST to meet the needs of the in-vitro diagnostic and research communities for a “higher order” reference material to obtain traceability to SI units. The SRM is stored and shipped frozen and must be thawed at room temperature before use.
