Next-Generation Lithium Testing: Diazyme’s Colorimetric Assay
Posted by Dr. Yuqi Huang, Assay Development Scientist at Diazyme Laboratories on 25th Jun 2025
Diazyme’s committed to innovations in clinical diagnostics. We are proud to spotlight Lead Scientist Dr. Yuqi Huang’s abstract presentation at ADLM 2025, showcasing the research behind our newly enhanced colorimetric lithium assay. Diazyme has submitted the newly developed assay for FDA’s review.
Dr. Huang’s poster highlights the importance of high precision testing in lithium monitoring and the technical advancements that improve test performance. The highlight of the presentation is shown below.
New Colorimetric Lithium Assay
Lithium carbonate has long stood as one of the most effective treatments for managing bipolar disorder, particularly manic-depressive psychosis. However, despite its therapeutic success, lithium’s narrow therapeutic index poses a significant risk—small deviations in dosage can lead to acute lithium toxicity. This makes precise and timely monitoring of serum lithium levels essential for patient safety. Recognizing this critical need, Dr. Yuqi Huang and the research team at Diazyme Laboratories have developed and validated an improved colorimetric lithium assay with enhanced performance and on-board stability. This innovation marks a significant step forward in clinical lithium monitoring, offering laboratories a cost-effective, easy-to-use, and highly accurate solution.
Why Lithium Monitoring Matters
Lithium works by altering neurotransmitter activity in the brain—affecting catecholamines, adenylate cyclase inhibition, and central nervous system amines. While it can stabilize mood swings and is increasingly being studied for potential benefits in conditions like Alzheimer’s disease, its narrow safety margin means that levels above 1.5 mmol/L (12 hours post-dose) can lead to toxicity, manifesting as confusion, tremors, and even organ failure.
Colorimetric Innovation: A Better Way to Measure Lithium
Traditional methods like ion selective electrodes (ISE), while effective, can be labor-intensive and costly. Diazyme’s colorimetric lithium assay offers a modern alternative. The assay is based on the formation of a lithium-porphyrin complex under alkaline pH, producing a measurable color change. The degree of absorbance correlates directly with the lithium concentration in the sample. Unlike complex multi-step protocols, Diazyme’s lithium assay is a single-reagent, spectrophotometric test that provides results in under a minute—ideal for high-throughput clinical laboratories.
Validated Performance on Widely Used Chemistry Analyzers
The assay was developed and validated on both the Roche Cobas c701 and the Beckman Coulter AU680 chemistry analyzers, demonstrating:
- Measuring range: 0.10 mmol/L – 3.00 mmol/L
- Limit of Quantification (LOQ): 0.10 mmol/L
- No interference from common serum components
- Improved reagent stability with the addition of a pH stabilizer
Historically, the high pH needed for colorimetric detection has compromised on-board reagent stability. Dr. Huang’s work included a innovative chemical stabilizer that maintains pH balance and ensures reliable performance throughout the assay’s shelf life.
Enabling Safer, Smarter Lithium Therapy
The improved lithium test enables physicians and laboratories in monitoring therapeutic lithium levels with greater confidence.
Stay Tuned
The test is being evaluated for regulatory approvals before being available commercially.