Label-free deep-UV microscopy detection and grading of neutropenia using a passive microfluidic device

Abstract

Neutropenia is a condition comprising an abnormally low number of neutrophils, a type of white blood cell, which puts patients at an increased risk of severe infections. Neutropenia is especially common among cancer patients and can disrupt their treatment or even be life-threatening in severe cases. Therefore, routine monitoring of neutrophil counts is crucial. However, the current standard of care to assess neutropenia, the complete blood count (CBC), is resource-intensive, time-consuming, and expensive, thereby limiting easy or timely access to critical hematological information such as neutrophil counts. Here, we present a simple technique for fast, label-free neutropenia detection and grading via deep-ultraviolet (deep-UV) microscopy of blood cells in polydimethylsiloxane (PDMS)-based passive microfluidic devices. The devices can potentially be manufactured in large quantities at a low cost, requiring only 1 μL of whole blood for operation. We show that the absolute neutrophil counts (ANC) obtained from our proposed microfluidic device-enabled deep-UV microscopy system are highly correlated with those from CBCs using commercial hematology analyzers in patients with moderate and severe neutropenia, as well as healthy donors. This work lays the foundation for the development of a compact, easy-to-use UV microscope system to track neutrophil counts that is suitable for low-resource, at-home, or point-of-care settings.

Deep learning-based analysis of deep ultraviolet (UV) microscopy images for label-free, point-of-care hematological analysis

“…Our method is both fast and efficient, capable of imaging and analyzing a 1mm X 2mm area (containing ¿20,000 cells) in approximately 3 minutes. Our automated analysis framework and low-cost microscope can be integrated with a microfluidic device 23 to create a single-wavelength-based, compact, automated point-of-care hematology analyzer that is well-suited for point-of-care, low-resource, at-home, and clinical settings, and will form part of future work.…”

“…Deep ultraviolet microscopy (UV) is a label-free imaging technique that relies on the characteristic spectral properties of endogenous biomolecules in this region of the spectrum (200-400 nm) to yield quantitative molecular and structural information from biological samples. 16,17,18,19,20,21,22,23,24 Deep-UV microscopy offers a higher spatial resolution than conventional methods because of the shorter wavelength of UV light. In addition, deep-UV microscopy enables contiguous imaging of live cells over long durations (> 6 hrs) without significant photodamage.…”

Multiparameter mobile blood analysis for complete blood count using contrast-enhanced defocusing imaging and machine vision

“…The requirements for preparing blood smears and searching for monolayer regions of blood smears for cell imaging may impede the device's applications by an untrained user. In our future study, we plan to combine the reported passive microfluid device 60 with our miniature microscope to improve and simplify the reported mobile blood analysis technique. In this manner, blood analysis can be performed by loading a drop of blood into a microchannel without requiring blood smears.…”

Deep-ultraviolet microscopy for analysis of bone marrow aspirate adequacy

“…Deep-ultraviolet (UV) microscopy enables label-free, high-resolution, quantitative molecular imaging by leveraging unique absorption properties of biomolecules, such as nucleic acids, in the UV region of the spectrum (200-400nm) [5][6][7][8]. Recently, it has been demonstrated for fast hematology analysis of whole blood smears and blood samples in custom microfluidic cartridges for point-of-care applications enabled by advancements in low-cost UV LEDs and sensors [9][10][11][12][13]. UV microscopy has also been used for multi-spectral, label-free histopathology of tissue samples [14][15][16].…”