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Matheson AB, Hopkinson C, Tanner MG, Henderson RK. Fluorescence lifetime imaging with distance and ranging using a miniaturised SPAD system. Sci Rep 2024; 14:13285. [PMID: 38858419 PMCID: PMC11164884 DOI: 10.1038/s41598-024-63409-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024] Open
Abstract
In this work we demonstrate a miniaturised imaging system based around a time-gated SPAD array operating in a "chip-on-tip" manner. Two versions of the system are demonstrated, each measuring 23 mm × 23 mm × 28 mm with differing fields of view and working distances. Initial tests demonstrate contrast between materials in widefield fluorescence imaging (WFLIm) mode, with frame rates of > 2 Hz achievable. Following this, WFLIm images of autofluorescence in ovine lung tissue are obtained at frame rates of ~ 1 Hz. Finally, the ability of the second system to perform simultaneous WFLIm and time of flight (aka Flourescence Lifetime Imaging Distance and Ranging, FLImDAR) is also tested. This shows that the system is capable of 4 mm resolution of object separation when tested on 3D printed samples. It is further demonstrated as being able to perform scene reconstruction on autofluorescent lung tissue. This system is, to date, the smallest chip on tip WFLIm system published, and is the first demonstration of the FLImDAR technique in a compact, portable system.
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Affiliation(s)
- Andrew B Matheson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK.
| | - Charlotte Hopkinson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Michael G Tanner
- School of Engineering and Physical Sciences, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Robert K Henderson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK
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Yuan X, Bowling A, Gemperline E, Mannam V, Howard S. Real-time, depth-resolved, in vivo multiphoton fluorescence lifetime imaging microscopy of agricultural herbicide treatments in plants. OPTICS EXPRESS 2024; 32:13733-13745. [PMID: 38859335 DOI: 10.1364/oe.507002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 02/13/2024] [Indexed: 06/12/2024]
Abstract
The development of effective and safe agricultural treatments requires sub-cellular insight of the biochemical effects of treatments in living tissue in real-time. Industry-standard mass spectroscopic imaging lacks real-time in vivo capability. As an alternative, multiphoton fluorescence lifetime imaging microscopy (MPM-FLIM) allows for 3D sub-cellular quantitative metabolic imaging but is often limited to low frame rates. To resolve relatively fast effects (e.g., photosynthesis inhibiting treatments), high-frame-rate MPM-FLIM is needed. In this paper, we demonstrate and evaluate a high-speed MPM-FLIM system, "Instant FLIM", as a time-resolved 3D sub-cellular molecular imaging system in highly scattering, living plant tissues. We demonstrate simultaneous imaging of cellular autofluorescence and crystalline agrochemical crystals within plant tissues. We further quantitatively investigate the herbicidal effects of two classes of agricultural herbicide treatments, photosystem II inhibiting herbicide (Basagran) and auxin-based herbicide (Arylex), and successfully demonstrate the capability of the MPM-FLIM system to measure biological changes over a short time with enhanced imaging speed. Results indicate that high-frame-rate 3D MPM-FLIM achieves the required fluorescence lifetime resolution, temporal resolution, and spatial resolution to be a useful tool in basic plant cellular biology research and agricultural treatment development.
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Matheson AB, Erdogan AT, Hopkinson C, Borrowman S, Loake GJ, Tanner MG, Henderson RK. Handheld wide-field fluorescence lifetime imaging system based on a distally mounted SPAD array. OPTICS EXPRESS 2023; 31:22766-22775. [PMID: 37475380 DOI: 10.1364/oe.482273] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/24/2023] [Indexed: 07/22/2023]
Abstract
In this work a handheld Fluorescent Lifetime IMaging (FLIM) system based on a distally mounted < 2 mm2 128 × 120 single photon avalanche diode (SPAD) array operating over a > 1 m long wired interface is demonstrated. The head of the system is ∼4.5 cm x 4.5 cm x 4.5 cm making it suitable for hand-held ex vivo applications. This is, to the best of the authors' knowledge, the first example of a SPAD array mounted on the distal end of a handheld FLIM system in this manner. All existing systems to date use a fibre to collect and relay fluorescent light to detectors at the proximal end of the system. This has clear potential biological and biomedical applications. To demonstrate this, the system is used to provide contrast between regions of differing tissue composition in ovine kidney samples, and between healthy and stressed or damaged plant leaves. Additionally, FLIM videos are provided showing that frame rates of > 1 Hz are achievable. It is thus an important step in realising an in vivo miniaturized chip-on-tip FLIM endoscopy system.
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Arief MAA, Kim H, Kurniawan H, Nugroho AP, Kim T, Cho BK. Chlorophyll Fluorescence Imaging for Early Detection of Drought and Heat Stress in Strawberry Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:1387. [PMID: 36987075 PMCID: PMC10057166 DOI: 10.3390/plants12061387] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/11/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
The efficiency of photosynthesis in strawberry plants is measured to maintain the quality and quantity of strawberries produced. The latest method used to measure the photosynthetic status of plants is chlorophyll fluorescence imaging (CFI), which has the advantage of obtaining plant spatiotemporal data non-destructively. This study developed a CFI system to measure the maximum quantum efficiency of photochemistry (Fv/Fm). The main components of this system include a chamber for plants to adapt to dark environments, blue LED light sources to excite the chlorophyll in plants, and a monochrome camera with a lens filter attached to capture the emission spectra. In this study, 120 pots of strawberry plants were cultivated for 15 days and divided into four treatment groups: control, drought stress, heat stress, and a combination of drought and heat stress, resulting in Fv/Fm values of 0.802 ± 0.0036, 0.780 ± 0.0026, 0.768 ± 0.0023, and 0.749 ± 0.0099, respectively. A strong correlation was found between the developed system and a chlorophyll meter (r = 0.75). These results prove that the developed CFI system can accurately capture the spatial and temporal dynamics resulting from the response of strawberry plants to abiotic stresses.
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Affiliation(s)
- Muhammad Akbar Andi Arief
- Department of Smart Agricultural System, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hangi Kim
- Department of Biosystems Machinery Engineering, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hary Kurniawan
- Department of Smart Agricultural System, Chungnam National University, Daejeon 34134, Republic of Korea
- Department of Agricultural Engineering, Faculty of Food Technology and Agroindustry, University of Mataram, Mataram 83115, Indonesia
| | - Andri Prima Nugroho
- Department of Agricultural and Biosystems Engineering, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
| | - Taehyun Kim
- Department of Agriculture Engineering, National Institute of Agricultural Science, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Byoung-Kwan Cho
- Department of Smart Agricultural System, Chungnam National University, Daejeon 34134, Republic of Korea
- Department of Biosystems Machinery Engineering, Chungnam National University, Daejeon 34134, Republic of Korea
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Bousgouni V, Inge O, Robertson D, Jones I, Clatworthy I, Bakal C. ARHGEF9 regulates melanoma morphogenesis in environments with diverse geometry and elasticity by promoting filopodial-driven adhesion. iScience 2022; 25:104795. [PMID: 36039362 PMCID: PMC9418690 DOI: 10.1016/j.isci.2022.104795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/27/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022] Open
Abstract
Rho GTP Exchange Factors (RhoGEFs) and Rho GTPase Activating Proteins (RhoGAPs) are large families of molecules that regulate shape determination in all eukaryotes. In pathologies such as melanoma, RhoGEF and RhoGAP activity underpins the ability of cells to invade tissues of varying elasticity. To identify RhoGEFs and RhoGAPs that regulate melanoma cell shape on soft and/or stiff materials, we performed genetic screens, in tandem with single-cell quantitative morphological analysis. We show that ARHGEF9/Collybistin (Cb) is essential for cell shape determination on both soft and stiff materials, and in cells embedded in 3D soft hydrogel. ARHGEF9 is required for melanoma cells to invade 3D matrices. Depletion of ARHGEF9 results in loss of tension at focal adhesions decreased cell-wide contractility, and the inability to stabilize protrusions. Taken together we show that ARHGEF9 promotes the formation of actin-rich filopodia, which serves to establish and stabilize adhesions and determine melanoma cell shape.
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Affiliation(s)
- Vicky Bousgouni
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Oliver Inge
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
- Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - David Robertson
- Division of Breast Cancer Research, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Ian Jones
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Innes Clatworthy
- Core Research Laboratories, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Chris Bakal
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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Assessment of Soil Fertility Using Induced Fluorescence and Machine Learning. SENSORS 2022; 22:s22124644. [PMID: 35746426 PMCID: PMC9227221 DOI: 10.3390/s22124644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 02/01/2023]
Abstract
Techniques such as proximal soil sampling are investigated to increase the sampling density and hence the resolution at which nutrient prescription maps are developed. With the advent of a commercial mobile fluorescence sensor, this study assessed the potential of fluorescence to estimate soil chemical properties and fertilizer recommendations. This experiment was conducted over two years at nine sites on 168 soil samples and used random forest regression to estimate soil properties, fertility classes, and recommended N rates for maize production based on induced fluorescence of air-dried soil samples. Results showed that important soil properties such as soil organic matter, pH, and CEC can be estimated with a correlation of 0.74, 0.75, and 0.75, respectively. When attempting to predict fertility classes, this approach yielded an overall accuracy of 0.54, 0.78, and 0.69 for NO3-N, SOM, and Zn, respectively. The N rate recommendation for maize can be directly estimated by fluorescence readings of the soil with an overall accuracy of 0.78. These results suggest that induced fluorescence is a viable approach for assessing soil fertility. More research is required to transpose these laboratory-acquired soil analysis results to in situ readings successfully.
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