Extraction of nucleic acids for in-vitro diagnostics
Reproducible dosing from 50 to 2000 µl in automated IVD systems
Sample preparation is a critical step in in-vitro diagnostics. Before analysis can take place, relevant target components must be isolated from patient samples such as blood, tissue, or cell material. In molecular diagnostic workflows, nucleic acids such as DNA and RNA are purified and prepared for downstream analysis.
The preparation process consists of several steps. Small reagent volumes between 50 and 200 µl are precisely dosed to selectively isolate target components from the sample. Larger liquid volumes of up to 2000 µl are subsequently used for washing and rinsing steps. Reproducible dosing across this entire volume range is essential for reliable diagnostic results.
What requirements does isolation of nucleic acids place on automated IVD systems?
Nucleic acid isolation requires precise dosing of different liquids as well as reliable cleaning of the fluidic system between patient samples. This is essential to achieve reproducible results and prevent cross-contamination.
Key requirements include:
- precise dosing of reagent volumes between 50 and 200 µl
- delivery of wash and rinse volumes up to 2000 µl
- high repeatability across a wide dosing range
- reliable separation of system liquid, sample, and reagents
- effective cleaning to prevent cross-contamination
- compact integration into automated diagnostic instruments
Complete cleaning of the sample loop requires high flow velocities to generate turbulent flow conditions and reliably remove residual liquids.
How is dosing implemented in automated IVD devices?
The system utilizes an mzr-4622 micro annular gear pump adapted for integration into automated IVD devices. For OEM applications, the pump is combined with an application-specific motor and integrated into the instrument’s fluidics architecture.
The pump performs both precise dosing of small reagent volumes and dynamic delivery of larger rinsing volumes. This allows dosing and cleaning processes to be realized using a single pump.
Fluid handling is performed through a sample loop located between the dosing needle and the pump. An air gap separates the system liquid from patient samples and reagents, enabling different media to be transported and dosed safely within the same fluidic system.
Multiple pumps are typically integrated into a single instrument. The pumps operate with low noise levels, require minimal maintenance, and are designed for many years of continuous operation.
What benefits does this provide for IVD device development?
By integrating the micro annular gear pump, diagnostic instruments can:
- perform DNA and RNA isolation reproducibly
- dose both small and large liquid volumes with high accuracy
- reduce the risk of cross-contamination between patient samples
- combine dosing and cleaning functions within a single fluidic architecture
- support compact and low-noise instrument designs
- achieve long maintenance intervals and high instrument availability
This OEM fluidic solution supports reproducible nucleic acid extraction across a wide dosing range and enables reliable separation, dosing, and cleaning with a single pump. As a result, it contributes to high process reliability and reproducible results in automated IVD instruments.