A lateral electrophoretic flow diagnostic assay

Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a “lateral e-flow assay” and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to selectively immobilize unmodified capture antigen along the microchannel in a barcode-like pattern. The channel-filling polyacrylamide hydrogel incorporates a photoactive moiety (benzophenone) to immobilize capture antigen to the hydrogel without a priori antigen modification. We report a heterogeneous sandwich assay using low-power electrophoresis to drive biospecimen through the capture antigen barcode. Fluorescence barcode readout is collected via a low-resource appropriate imaging system (CellScope). We characterize lateral e-flow assay performance and demonstrate a serum assay for antibodies to the hepatitis C virus (HCV). In a pilot study, the lateral e-flow assay positively identifies HCV+ human sera in 60 min. The lateral e-flow assay provides a flexible format for conducting multiplexed immunoassays relevant to confirmatory diagnosis in near-patient settings

Quantitative imaging with a mobile phone microscope.

Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone-based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications

Cytoplasmic volume modulates spindle size during embryogenesis.

Rapid and reductive cell divisions during embryogenesis require that intracellular structures adapt to a wide range of cell sizes. The mitotic spindle presents a central example of this flexibility, scaling with the dimensions of the cell to mediate accurate chromosome segregation. To determine whether spindle size regulation is achieved through a developmental program or is intrinsically specified by cell size or shape, we developed a system to encapsulate cytoplasm from Xenopus eggs and embryos inside cell-like compartments of defined sizes. Spindle size was observed to shrink with decreasing compartment size, similar to what occurs during early embryogenesis, and this scaling trend depended on compartment volume rather than shape. Thus, the amount of cytoplasmic material provides a mechanism for regulating the size of intracellular structures

Selective prophylactic calcium supplementation reduces length of stay after total thyroidectomy

Introduction: Hypocalcemia is a common complication of thyroidectomy. We aimed to assess compliance with a targeted calcium and calcitriol supplementation protocol and hypothesized that it would allow safe early discharge without an increase in readmissions. Materials and methods: In 2009, we instituted a targeted early postoperative calcium and calcitriol supplementation protocol based on postoperative parathyroid hormone (PTH). We retrospectively reviewed all patients who had a total or completion thyroidectomy over a 4-year period prior to protocol implementation (group I: 2005–2008) and over a 5-year period after protocol implementation (group II: 2010–2014), as well as all patients operated on in the private setting with the senior author over a 1-year period (group III: 2013). Endpoints for analysis were clinically significant hypocalcemia, protocol compliance, hospital length of stay (LOS), and readmission for hypocalcemia. Results: Compliance with the protocol was high; however, the accuracy of supplementation prescription was significantly lower in group II than in group III (p < 0.0001). Mean corrected calcium on postoperative day 1 was significantly higher in groups II (2.29 mmol/L) and III (2.27 mmol/L) compared with group I (2.15 mmol/L; p < 0.0001). Forty (30.5%) patients had clinically significant hypocalcemia in group I, compared with 21 (10.8%) in group II, and 2 (3.3%) in group III (p < 0.0001). The LOS was significantly decreased after protocol introduction (p < 0.0001). Conclusion: Selective prophylactic calcium supplementation reduces LOS after total thyroidectomy. Clinical significance: Introducing a new management protocol in the public hospital system poses challenges with compliance; however, it was successful in lowering rates of symptomatic hypocalcemia and LOS without an increase in the readmission rate

Mobile phones differ from scientific cameras in selection of image capture and processing parameters.

<p><b>A</b> Common core hardware components underlie the capture process of both mobile phone cameras and scientific cameras. <b>B</b> The capture and processing parameters are set directly through the user interface of a scientific camera. <b>C</b> On mobile phones, an intermediate layer assesses the view of the camera in real-time and modifies image acquisition. This simplifies the user interface for traditional point-and-shoot photography but sacrifices the control desired by a scientific user.</p

A multi-phone mobile microscope.

<p><b>A</b> Diagram of the magnifying optics and illumination added to a mobile phone to create a transmission light microscope. <b>B</b> Prototype of a field-ready mobile microscope – the CellScope – that has a folded optical path for compactness and is equipped with a multi-phone holder and iPhone 4. Phone-specific variants have been evaluated on five continents for various applications. <b>C</b> A Wright stained blood smear taken on the mobile microscope with an iPhone 4 and 20×/0.4 NA objective showing the inscribed field of view captured by the device. <b>D</b> Enlarged images of the small region of interest in <b>C</b> containing a granulocyte and red blood cells taken with four different mobile phones. The images demonstrate resolution, color, and brightness differences among phones.</p

A lateral electrophoretic flow diagnostic assay.

Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a "lateral e-flow assay" and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to selectively immobilize unmodified capture antigen along the microchannel in a barcode-like pattern. The channel-filling polyacrylamide hydrogel incorporates a photoactive moiety (benzophenone) to immobilize capture antigen to the hydrogel without a priori antigen modification. We report a heterogeneous sandwich assay using low-power electrophoresis to drive biospecimen through the capture antigen barcode. Fluorescence barcode readout is collected via a low-resource appropriate imaging system (CellScope). We characterize lateral e-flow assay performance and demonstrate a serum assay for antibodies to the hepatitis C virus (HCV). In a pilot study, the lateral e-flow assay positively identifies HCV+ human sera in 60 min. The lateral e-flow assay provides a flexible format for conducting multiplexed immunoassays relevant to confirmatory diagnosis in near-patient settings