Technology
Integrated Fluidics’ new assay platform represents a true breakthrough in micro-plate assay performance. Electrodes incorporated into the base of the microplate enable the delivery of electrical impulses of specific amplitude and frequency. Precise control of the resulting hydro-dynamic forces within each well of the micro-plate enables molecular mixing, separation and concentration at the <5 microliter-scale.
What has, until now, been a passive, plastic reaction vessel is transformed into an active, user-controlled reaction management system.
The Integrated Fluidics Assay Platform
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A simple software interface enables the operator to enter bioassay-specific parameters
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Full Platform includes Power Supply with Stage unit V2.2
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Proprietary Software controls the processing.
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A software-driven, low-cost power supply generates bioassay-specific electrical impulses and delivers them to a temperature-controlled micro-plate stage.
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Electrokinetically-enabled micro-plates ("iPlates") replace conventional micro-plates. Laboratory workflow is unchanged.
Rapid and accurate biosensing with low concentrations of the analytes is usually challenged by diffusion-limited reaction kinetics. Thus, long incubation times or excess amounts of the reagents are employed in biosensor and diagnostic platforms to ensure the reactions go to completion.
Here we propose a technology that provides electro mixing of the reagents in solutions where the incubation times, or in other words, the time required for the desired molecules to meet in stationary solutions, can be reduced substantially.
This technology has been applied to an immunoassay-based diagnostic kit for diabetes (glycated hemoglobin (HbA1c) test) and FRET-based quenching bio platform consisting of a molecular beacon DNA and gold nanoparticles in electrode-enabled microwell plates as called as iPlates. When electro mixing was employed, the incubation times were reduced by approximately a factor of 5 and 4 for the diabetes diagnostic kit and FRET-based quenching bio platform, respectively.
This technology has been applied to an immunoassay-based diagnostic kit for diabetes (glycated hemoglobin (HbA1c) test) and FRET-based quenching bio platform consisting of a molecular beacon DNA and gold nanoparticles in electrode-enabled microwell plates as called as iPlates. When electromixing was employed, the incubation times were reduced by approximately a factor of 5 and 4 for the diabetes diagnostic kit and FRET-based quenching bio platform, respectively. Furthermore, suppose the quantity of the reagents was further reduced by half, where almost no distinguishable signals could be obtained with conventional immunoassay, electromixing still facilitated the acquisition of signals while varying the concentration of the glycated hemoglobin(HbA1c).
Furthermore, suppose the quantity of the reagents was further reduced by half, where almost no distinguishable signals could be obtained with conventional immunoassay. In that case, electro mixing still facilitates the acquisition of signals while varying the concentration of the glycated hemoglobin (HbA1c).
Electrokinetic Mixing for Improving the Kinetics of an HbA1c Immunoassay
CONCLUSION
HbA1c immunoassay that detects glycated hemoglobin was chosen as a pilot diagnostic kit, and its overall incubation time was reduced by approximately five times from 90 minutes to 20 minutes by utilizing electro mixing.
When the quantity of the HbA1c kit reagents was reduced by half, almost no distinguishable signals could be obtained with conventional immunoassay, whereas electro mixing could still facilitate acquiring signals with higher intensities while varying the concentration of the glycated hemoglobin. This demonstrates that electro mixing can provide cost-efficient biological assays.
Moreover, there is a substantial difference in the signal intensities, especially for the lower concentrations of the antigen obtained from electro mixing assisted (dynamic mixing) and conventional immunoassays of HbA1c when the quantity of the reagents and incubation times were kept constant. Thus, electro mixing could be helpful for the low abundant target biomolecule detections.
In the other case, when the diffusion limitation is still significant, the proposed electro mixing method could improve the fluorescence quenching kinetics of the chosen molecular beacon DNA by up to approximately four times.
Since AuNPs were used to quench molecular beacon DNAs, electo mixing may also be employed to speed up the surface modification of nano/microparticles.
In summary, electro mixing as a novel method has a huge potential to improve the efficiency of the current point of care devices, diagnostic and biosensor platforms utilizing microwell plates so that rapid, accurate, cost-efficient, and high throughput analysis of clinical samples may be achieved.
This work is supported by grants awarded by the ARO MURI
https://www.nature.com/articles/s41598-019-56205-4 --> HbA1c Immunoassay
https://www.sciencedirect.com/science/article/abs/pii/S000326702030146X#undfig1 --> FRET based quenching bioplatform with DNA/AuNPs