Diagnostic Enzymes & IVD
Blood Ketone Testing Enzyme Solutions
Enzyme solution development and qualification for beta-hydroxybutyrate measurement in point-of-care and laboratory ketone testing.
BHBDH and NAD+ signal generation
The core reaction oxidizes beta-hydroxybutyrate to acetoacetate and produces NADH, which is read electrochemically or optically.
- Beta-hydroxybutyrate dehydrogenase (BHBDH) as the analyte-specific enzyme
- NAD+ cofactor and buffer components tuned for enzyme activity
- Signal proportional to beta-hydroxybutyrate concentration
Beta-hydroxybutyrate over other ketones
Blood ketone tests differ in which ketone bodies they measure, and results are not interchangeable across methods.
- Beta-hydroxybutyrate is the predominant ketone body in severe DKA
- Urine methods typically measure acetoacetate or acetoacetate and acetone, and they do not usually detect beta-hydroxybutyrate.
- Method-specific specificity documentation is part of the qualification package
Point-of-care and laboratory compatibility
Enzyme solutions are formulated for the readout format the customer's device or analyzer uses.
- Handheld meter and test-strip formats
- Laboratory analyzer and cartridge formats
- Compatibility assessment against the customer's strip or cartridge design
Why Enzyme Quality Matters
Point-of-care ketone testing has changed how DKA is detected: results are typically available within 30–60 seconds, and direct beta-hydroxybutyrate measurement correlates better with metabolic status than urine acetoacetate levels. That speed and accuracy depend on the enzyme solution behaving consistently across lots, storage conditions, and device formats.
Several factors influence point-of-care accuracy, including haematocrit variation, extreme temperatures, and improper calibration. Reagent strips also have relatively short shelf lives, and interference from high triglyceride levels or other metabolites may occasionally affect readings. Enzyme solution stability, specificity, and calibration design are therefore central to the analytical performance a ketone meter can deliver.
| Performance dimension | Why it matters | What we characterize | Typical project scope |
|---|---|---|---|
| Enzyme activity | Defines the signal generated per unit of beta-hydroxybutyrate | Activity units under defined reaction conditions | Activity definition and assay conditions scoped per project |
| Specificity | Blood ketone methods are not interchangeable across ketone bodies | Response to beta-hydroxybutyrate relative to other ketone bodies | Specificity panel scoped per project |
| Stability | Reagent strips have relatively short shelf lives and are sensitive to storage | Activity retention under defined storage conditions | Stability study design scoped per project |
| Calibration | Improper calibration is a recognized influence on point-of-care accuracy | Calibrator and QC material design for ketone meters | Calibration and QC materials scoped per project |
How Engagement Works
Projects follow a defined sequence from enzyme solution design through analytical qualification and transfer, with scope agreed in the SOW before work begins.
Define the analytical target
We agree the analyte, the intended sample type (whole blood, serum, or plasma), the readout format, and the clinical context the assay must support.
Formulate the enzyme solution
Beta-hydroxybutyrate dehydrogenase is combined with NAD+ cofactor and buffer components selected for activity, specificity, and compatibility with the customer's strip or cartridge.
Qualify activity and specificity
Enzyme activity is measured under defined reaction conditions, and response to beta-hydroxybutyrate is characterized relative to other ketone bodies.
Build calibration and QC materials
Calibrators and quality control materials are prepared for ketone meters, with the calculations and reference conditions documented for the customer's device.
Customization Options
Enzyme solution composition, analytical depth, and documentation are defined case by case against the customer's device, sample type, and regulatory pathway.
Enzyme and cofactor composition
BHBDH concentration, NAD+ cofactor level, and buffer components are adjusted for the intended reaction conditions and readout.
- Enzyme and cofactor levels scoped per project
- Buffer and stabilizer selection scoped per project
- Compatibility with strip or cartridge chemistry
Whole blood, serum, or plasma
Formulation and qualification are aligned to the sample matrix the device is intended to measure.
- Fingerstick whole blood for handheld meters
- Serum or plasma for laboratory testing
- Matrix-specific handling and dilution considerations
Activity, specificity, and stability testing
The analytical package is built around the claims the customer needs to support.
- Activity units and reaction conditions
- Specificity relative to other ketone bodies
- Stability and storage-condition assessment
Service Scope
Scope, analytical depth, and documentation are defined in the project SOW after consultation. The table below describes what can be customized case by case.
| Parameter | Typical project scope | Customer input | Documentation |
|---|---|---|---|
| Enzyme solution formulation | BHBDH with NAD+ cofactor and buffer components, adjusted for the intended readout | Device format, sample type, target reaction conditions | Formulation record and reaction conditions |
| Activity definition | Activity units measured under defined reaction conditions | Required unit definition and assay temperature | Activity method and calculation |
| Specificity assessment | Response to beta-hydroxybutyrate relative to other ketone bodies | Interferents and concentration ranges of interest | Specificity panel results |
| Stability and shelf-life | Activity retention under defined storage conditions | Storage conditions and target shelf-life | Stability study summary |
| Calibration and QC materials | Calibrators and quality control materials for ketone meters | Calibration model and QC acceptance criteria | Calibration and QC documentation |
| Device bridging | Assessment in the intended point-of-care or laboratory analyzer format | Strip or cartridge design and analyzer platform | Bridging and transfer records |
| Technical support | A named scientific contact is assigned at project start, milestone review calls are scheduled, and email inquiries receive a response within 1 business day. | Project contacts and review cadence | Milestone review notes |
Applications and Clinical Context
Blood ketone testing is primarily used to screen for, detect, and monitor diabetic ketoacidosis in people with type 1 and sometimes type 2 diabetes, and is also used when ketoacidosis is suspected in people without diabetes, such as alcoholic ketoacidosis or prolonged starvation. Ketosis and ketoacidosis may also be seen with high-fat, low-carbohydrate diets and in children with epilepsy whose seizures do not respond to available medications.
Enzyme solutions developed for these applications must support the clinical decision the device is used for, including interpretation against clinical cutoffs for DKA.
Screening and monitoring
Blood ketones are used to screen for, detect, and monitor DKA, a sometimes life-threatening complication of diabetes.
- Symptoms include increased urination, excessive thirst, dehydration, rapid breathing, and shortness of breath.
- Testing may be performed when there is potential for DKA to develop, such as during illness or pregnancy.
- Interpretation against clinical cutoffs for DKA
Hospital, clinic, and home
Point-of-care ketone testing supports timely decision-making in emergency departments, intensive care, clinics, and home monitoring.
- Near-patient testing in hospital and emergency settings
- Primary care and outpatient identification of ketosis
- Home self-testing with handheld meters
Other ketosis contexts
Ketone measurement is also relevant outside diabetes, including alcoholic ketoacidosis and prolonged starvation.
- Alcoholic ketoacidosis (AKA)
- Prolonged starvation and ketogenic diets
- Monitoring during fasting or exercise regimens
Analytical Considerations
Point-of-care ketone devices have recognized limitations that enzyme solution design and qualification should account for. Accuracy can be influenced by haematocrit variation, extreme temperatures, or improper calibration, and reagent strips have relatively short shelf lives. Interference from high triglyceride levels or other metabolites may occasionally affect readings, though modern sensors are designed to minimize such errors.
There is also a documented patient-safety dimension: reviews of incident data have identified wrong strip selection due to visual similarity, local labelling, and storage issues, including cases where a ketone result was interpreted as a blood glucose result. Enzyme solution and strip design work should therefore be considered alongside labelling, storage, and operator training requirements.
| Consideration | Reported influence | Design response | Project scope |
|---|---|---|---|
| Haematocrit variation | Can influence point-of-care accuracy | Formulation and calibration strategy for the intended sample matrix | Scoped per project |
| Temperature | Extreme temperatures can influence accuracy | Stability and operating-range assessment | Scoped per project |
| Calibration | Improper calibration is a recognized influence on accuracy | Calibrator and QC material design | Scoped per project |
| Strip shelf life | Reagent strips have relatively short shelf lives | Storage-condition and activity-retention studies | Scoped per project |
| Strip selection errors | Wrong strip selection has been linked to visual similarity, labelling, and storage issues | Design and documentation inputs to labelling and storage requirements | Scoped per project |
Documentation and Transfer
Each project produces a documentation set that describes the enzyme solution, the analytical methods used to qualify it, and the conditions under which the results were obtained. This supports the customer's internal quality and regulatory activities.
Transfer documentation is prepared so the customer can reproduce the defined reaction conditions and calculations in their own device or analyzer format.
Working With Our Team
Projects begin with a technical discussion covering the analyte, sample type, device format, and the analytical claims the customer needs to support. From there, scope, analytical depth, and documentation are agreed in the SOW.
A named scientific contact is assigned at project start, with milestone review calls and email response within 1 business day.
FAQ
Which enzyme is used in enzymatic blood ketone testing?
Enzymatic blood ketone testing uses beta-hydroxybutyrate dehydrogenase (BHBDH) to oxidize beta-hydroxybutyrate to acetoacetate, generating NADH that is measured electrochemically or optically. The signal is proportional to beta-hydroxybutyrate concentration, the predominant ketone body in blood during severe diabetic ketoacidosis.
Why measure beta-hydroxybutyrate rather than acetoacetate?
Beta-hydroxybutyrate is the predominant ketone body present in severe diabetic ketoacidosis, and direct beta-hydroxybutyrate measurement correlates better with metabolic status than urine acetoacetate levels. Urine methods typically measure acetoacetate or acetoacetate and acetone and do not usually detect beta-hydroxybutyrate, so results across methods are not interchangeable.
Can the enzyme solution be adapted to our strip or analyzer format?
Yes. Formulation and qualification are aligned to the intended readout format, whether that is a handheld meter and test strip or a laboratory analyzer and cartridge. Compatibility assessment against the customer's strip or cartridge design is part of the project scope, defined case by case in the SOW.
How is enzyme solution stability addressed?
Reagent strips have relatively short shelf lives and are sensitive to storage conditions, so stability work focuses on activity retention under defined storage conditions. The study design, storage conditions, and target shelf-life are agreed per project and documented in a stability summary.
What calibration and QC support is available for ketone meters?
Calibrators and quality control materials for ketone meters can be prepared as part of the project, with the calibration model and QC acceptance criteria agreed with the customer. Improper calibration is a recognized influence on point-of-care accuracy, so this work is documented alongside the activity and specificity results.
How does this differ from urine ketone testing?
Urine ketone tests rely on nitroprusside reagents that detect acetoacetate and, to a lesser extent, acetone, and they do not usually detect beta-hydroxybutyrate. Enzymatic blood ketone testing directly quantifies beta-hydroxybutyrate and reflects the patient's current metabolic state, which is why it is used for DKA detection and monitoring.
References
- Cai W, Chong K, Huang Y, et al. Empagliflozin improves mitochondrial dysfunction in diabetic cardiomyopathy by modulating ketone body metabolism and oxidative stress. Redox biology. 2024;69:103010. View on PubMed
- Garg R, Karmakar E, DeBruin D, et al. BDH1-Dependent Ketone Body Metabolism Maintains Müller Cell Homeostasis and Retinal Function. bioRxiv: the preprint server for biology. 2025 Dec 27. View on PubMed
Discuss your ketone enzyme project
Share your analyte, sample type, and device format, and we will define a project scope covering enzyme solution formulation, activity and specificity qualification, calibration and QC materials, and bridging to your point-of-care or laboratory analyzer format.