Very wide field of view imaging can be used in biology to infer statistical information on cell populations from a singleshot acquisition. In particular, for applications in hematology, fluorescence wide-field of view imaging could be an alternative to standard fluorescence flow cytometry methods; it can be useful to achieve standard blood tests, such a leukocyte count or leukocyte differential count. We will introduce two 30mm2 wide-field fluorescence imaging set-ups and compare their performances. Both systems achieve 1x magnification. The first one is based on a macro-photography lens. Although such a system optimizes the resolution and field of view, it suffers from its bulkiness. With the second system, we seek miniaturization while loosening the requirements on image quality. It is based on a lens-less approach with a fiber plate optical relay. The potential of the two systems for hematology analyzes will be illustrated with the imaging of labelled white blood cells.
Phase and fluorescence are complementary contrasts that are commonly used in biology. However, the coupling of these two modalities is traditionally limited to high magnification and complex imaging systems. For statistical studies of biological populations, a large field-of-view is required. We describe a 30 mm2 field-of-view dual-modality mesoscope with a 4-μm resolution. The potential of the system to address biological questions is illustrated on white blood cell numeration in whole blood and multiwavelength imaging of the human osteosarcoma (U2-OS) cells.
Very wide-field of view imaging can provide statistical data on large cell populations in a single acquisition. In this paper, we describe a multimodal imaging system combining brightfield, phase and fluorescence contrasts. Its greater simplicity and lower cost compared to flow cytometry make it suitable for Point-Of-Care applications. The system’s resolution was characterized on calibrated beads and resolution targets. We illustrate the potential of the single-shot imaging approach in hematology by studying the specific morphologies of white blood cell sub-types. The results suggest that very wide field of view imaging could be an alternative to flow cytometry for some applications in hematology.
Lensfree in-line holography permits to image large fields of view with resolution of few micrometers. By adding a fluorescence microscopy detection pathway, we can simultaneously image samples with a better resolution and a complementary contrast.