Publications by authors named "Janosch Hauser"

Rapid on-site evaluation (ROSE) increases the diagnostic accuracy of fine-needle aspiration (FNA) samples from cysts, a sack-like fluid-containing tissue that sometimes can be precancerous, but is highly dependent on the skills and availability of cytopathologists. We present a semiautomated sample preparation device for ROSE. The device consists of a smearing tool and a capillary-driven chamber that allow smearing and staining of an FNA sample in a single platform.

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Patient-centric sampling strategies, where the patient performs self-sampling and ships the sample to a centralized laboratory for readout, are on the verge of widespread adaptation. However, the key to a successful patient-centric workflow is user-friendliness, with few noncritical user interactions, and simple, ideally biohazard-free shipment. Here, we present a capillary-driven microfluidic device designed to perform the critical biomarker capturing step of a multiplexed immunoassay at the time of sample collection.

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Performing complete blood counts from patients' homes could have a transformative impact on e-based healthcare. Blood microsampling and sample drying are enabling elements for patient-centric healthcare. The aim of this study was to investigate the potential of dry blood samples for image-based cell quantification of red and white blood cells.

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Rapid on-site evaluation (ROSE) significantly improves the diagnostic yield of fine needle aspiration (FNA) samples but critically depends on the skills and availability of cytopathologists. Here, we introduce a portable device for semi-automated sample preparation for ROSE. In a single platform, the device combines a smearing tool and a capillary-driven chamber for staining FNA samples.

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Transmission electron microscopy (TEM) allows for visualizing and analyzing viral particles and has become a vital tool for the development of vaccines and biopharmaceuticals. However, appropriate TEM sample preparation is typically done manually which introduces operator-based dependencies and can lead to unreliable results. Here, we present a capillary-driven microfluidic single-use device that prepares a TEM grid with minimal and non-critical user interaction.

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Obtaining plasma from a blood sample and preparing it for subsequent analysis is currently a laborious process involving experienced health-care professionals and centrifugation. We circumvent this by utilizing capillary forces and microfluidic engineering to develop an autonomous plasma sampling device that filters and stores an exact amount of plasma as a dried plasma spot (DPS) from a whole blood sample in less than 6 min. We tested 24 prototype devices with whole blood from 10 volunteers, various input volumes (40-80 μL), and different hematocrit levels (39-45%).

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Whole-blood microsampling provides many benefits such as remote, patient-centric, and minimally invasive sampling. However, blood plasma, and not whole blood, is the prevailing matrix in clinical laboratory investigations. The challenge with plasma microsampling is to extract plasma volumes large enough to reliably detect low-concentration analytes from a small finger prick sample.

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A sensitive photoacoustic absorption spectrometer for highly transparent solids has been built and tested. As the light source an optical parametrical oscillator pumped by a nanosecond pulse laser with 10 Hz repetition rate is employed, covering the complete wavelength range from 407 to 2600 nm. A second-harmonic-generation unit extends the range of accessible wavelengths down to 212 nm.

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