Blood ammonia (AMM, NH₃) is a core biomarker for assessing liver function and hepatic encephalopathy. It is primarily produced through amino acid metabolism and intestinal decomposition and absorption, and is metabolized and excreted via the hepatic urea cycle [1]. When liver function is impaired (e.g., in hepatitis or cirrhosis), blood ammonia metabolism is obstructed, and its concentration rises, which in severe cases can trigger hepatic encephalopathy. Therefore, blood ammonia detection is of great clinical significance for the diagnosis, treatment, and prognosis of liver diseases.

Figure 1. Ammonia Toxicity Hypothesis of Hepatic Encephalopathy

(Pathogenesis of the ammonia toxicity hypothesis: Ammonia is produced from the breakdown of proteins and other substances in the gastrointestinal tract. Liver insufficiency prevents blood ammonia from being effectively detoxified through the urea cycle. Meanwhile, portosystemic shunting causes ammonia-containing portal venous blood to directly enter the systemic circulation [2], cross the blood-brain barrier into brain tissue, produce neurotoxicity, and ultimately induce hepatic encephalopathy.)

Currently, blood ammonia detection predominantly uses the glutamate dehydrogenase method. Common single-reagent and dual-reagent formulations on the market each have their own pain points:

●   Dual reagents: After opening, prolonged exposure to air makes them prone to absorbing environmental ammonia and ammonia produced by internal protein degradation, resulting in poor on-board stability. Laboratory personnel are forced to perform frequent calibrations and quality controls, increasing workload and costs.

●  Single reagents: Although they can eliminate ammonia interference from non-sample factors, because the signal is read in the early stage of the reaction, they cannot exclude interference from pyruvate, chylomicrons, and other substances in the sample, resulting in poor anti-interference capability and low sensitivity with large test fluctuations—producing unreliable measurements that cannot be confidently reported.

Single reagents solve the stability problem but sacrifice accuracy; dual reagents maintain accuracy but cannot sustain stability. Laboratory personnel face a dilemma: either calibrate frequently or accept unreliable results.

01  Upgraded On-Board Stability

Addressing the clinical pain points of reagents readily absorbing ammonia from the air and coenzyme degradation, Snibe has innovatively adopted an "in-situ clearance" strategy, enabling reagents to eliminate background ammonia while open and on-board, ensuring that only ammonia in the sample participates in subsequent reactions (Figure 2).

Figure 2. Schematic Diagram of In-Situ Clearance Technology

Measured data show that the Snibe AMM reagent achieves long-term stability of 28 days with a single calibration, with quality control deviations strictly controlled within ±10% during the 28-day on-board period (Figure 3).

Figure 3. Comparison of Quality Control Charts Within 28 Days After Opening the AMM Reagent

02  Upgraded Anti-Interference Capability

The glutamate dehydrogenase method detects at a wavelength of 340 nm, which is susceptible to lipemia interference. This interference is further exacerbated by the large proportion of the sample in the reaction system. With the rising global trend of obesity, the anti-lipemia capability of blood ammonia testing still needs improvement. To address this, Snibe employs a multi-surfactant compound technology that thoroughly removes lipemic substances before the main reaction, eliminating interference at the source.

▶  Anti-fat emulsion interference:

▶  Anti-real lipemia interference:

When testing lipemic samples of varying degrees (mild, moderate, severe), the relative deviations of Snibe AMM reagent results before and after dilution are all controlled within ±10%, demonstrating excellent anti-lipemia interference capability.

03  Upgraded User Experience

Snibe AMM reagent innovatively applies "in-situ clearance technology" and "multi-surfactant compound technology," successfully solving the dilemma where traditional reagents cannot simultaneously achieve on-board stability and anti-interference capability. At the same time, it balances precision and convenience, providing clinical laboratories with a more efficient and reliable blood ammonia testing solution, and effectively reducing the burden on laboratory departments.

References:

[1] Ma Linqin, Wu Caijun. Research progress on the application of blood ammonia detection in the field of acute and critical illness [J]. Chinese Journal of Emergency Medicine, 2018, 27(10): 1179-1183.

[2] Elliot B. Tapper, Zhigang Jiang, Vilas Patwardhan. Refining the Ammonia Hypothesis. Mayo Clinic Proceedings. 2015;90(5):646-658.