Microdialysis is one of the few methods available to accurately determine quantities of various substances in freely moving animals.
Our team includes some of the pioneers in the field. But we go far beyond conventional and push-pull methods, having developed our own proprietary technique – MetaQuant – for accurately measuring free-drug concentrations in tissue and plasma.
Client-developed compound showed clear behavioral phenotype, but mechanism of action was unclear.
We designed a study to combine conventional microdialysis with MetaQuant, plasma and CSF sampling to monitor a range of neurotransmitters, potential biomarkers, and free-drug concentrations in different compartments simultaneously.
To elucidate mechanism of action for client-developed compound.
One particular biomarker was elevated in a dose-related manner, and increased in brain, CSF and plasma as peak drug concentrations were achieved. Based on this study, the compound was taken forward into development. Later, the marker was subsequently used as a clinical biomarker in later-stage trials.
Neurotransmitters / Pharmacology
Conventional microdialysis probes are used to measure local release of neurotransmitters and other small endogenous substances in freely moving or anesthetized rodents.
- Amino acids
- Trace amines
- Kynurenine metabolites
- Monoamine metabolites
- Cyclic nucleotides
For a complete list of the neurotransmitters we measure, click here »
Push-Pull – Proteins / Peptides / Antibodies
For recovery of larger molecules, push-pull microdialysis uses larger pore sizes in the dialysis membrane. Compared to conventional dialysis, push-pull allows the measurement of larger endogenous proteins, inflammatory mediators, peptides and exogenously applied antibodies.
Large molecules we measure include:
MetaQuant – Pharmacokinetics
Typically, free-drug concentrations in tissue are calculated by measuring the total drug concentration, then subtracting the bound-drug, based on an in vitro protein binding calculation. Our proprietary MetaQuant probe allows for accurate measurement of actual free-drug concentrations, vs. inferred concentration based on standard calculations. This means truly quantitative dialysis, which saves time and money in the process.
- No more anomalies between in vitro and in vivo data
- Fewer animals required for testing
- Fast turnover without extensive validation required
- Ability to track over time from the same animal, and in combination with other techniques
Multiple Probes (PK/PD) – Combination
Our deep experience with microdialysis enables a wide range of options for combining various probes across a broad array of applications. We can customize to your specific needs by combining PK or PD microdialysis techniques with each other, or with behavior, EEG, etc.
- Measure free brain levels
- Measure free blood concentrations
- Collect samples for identification of potential translational biomarkers
- Measure pharmacodynamic changes in neurotransmitters, modulators, and proteins in real-time, while collecting free-drug concentrations to build accurate PK/PD relationships
Microdialysis of other tissues
With our expertise in microdialysis, and a strategic partnership with Brainlink that provides us customizable microdialysis probes, we are able to perform microdialysis in various tissues. To date, we have performed microdialysis in the GI tract, heart, liver, bone, kidney, lung, eye, and skin tissue. Many of these techniques have been optimized for a freely moving environment.