Patent ID: 11921124
Assignee: SIEMENS HEALTHCARE DIAGNOSTICS INC.
Field: Measurement (Instruments)
Classification: CPC G  A  C | IPC A  C  G

Claim 17:
18. A composition comprising an aqueous diagnostic quality control or calibration reagent for calibration or quality control of a blood urea nitrogen (BUN) or creatinine sensor, wherein the aqueous diagnostic quality control or calibration reagent is disposed in a closed system, the composition comprising:
urea present in a concentration in a range of from about 0.1 mM to about 150 mM;
at least one buffer;
asparagine, wherein a ratio of urea to asparagine is in a range of from about 0.1:1 to about 100:1; and
wherein the aqueous diagnostic quality control or calibration reagent is free of protein;
wherein an original pH of the aqueous quality control or calibration reagent is in a range of from about 6 to about 8, and wherein the pH of the aqueous quality control or calibration reagent varies by +/−1.0 or less of the original pH following storage of the composition, and further wherein formation of ammonia in the aqueous diagnostic quality control or calibration reagent is substantially reduced by at least 5% following storage of the composition when compared to a composition prepared in the absence of asparagine and following storage thereof; and
wherein the aqueous diagnostic quality control or calibration reagent is brought into direct contact with the BUN or creatinine sensor for calibration or quality control of the BUN or creatinine sensor.