1
|
Shaw TR, Fazekas FJ, Kim S, Flanagan-Natoli JC, Sumrall ER, Veatch SL. Estimating the localization spread function of static single-molecule localization microscopy images. Biophys J 2022; 121:2906-2920. [PMID: 35787472 PMCID: PMC9388596 DOI: 10.1016/j.bpj.2022.06.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/17/2022] [Accepted: 06/29/2022] [Indexed: 11/27/2022] Open
Abstract
Single-molecule localization microscopy (SMLM) permits the visualization of cellular structures an order of magnitude smaller than the diffraction limit of visible light, and an accurate, objective evaluation of the resolution of an SMLM data set is an essential aspect of the image processing and analysis pipeline. Here, we present a simple method to estimate the localization spread function (LSF) of a static SMLM data set directly from acquired localizations, exploiting the correlated dynamics of individual emitters and properties of the pair autocorrelation function evaluated in both time and space. The method is demonstrated on simulated localizations, DNA origami rulers, and cellular structures labeled by dye-conjugated antibodies, DNA-PAINT, or fluorescent fusion proteins. We show that experimentally obtained images have LSFs that are broader than expected from the localization precision alone, due to additional uncertainty accrued when localizing molecules imaged over time.
Collapse
Affiliation(s)
- Thomas R Shaw
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan; Program in Applied Physics, University of Michigan, Ann Arbor, Michigan
| | - Frank J Fazekas
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Sumin Kim
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan
| | | | - Emily R Sumrall
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Sarah L Veatch
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan; Program in Applied Physics, University of Michigan, Ann Arbor, Michigan.
| |
Collapse
|
2
|
Shang M, Huang ZL, Wang Y. Influence of drift correction precision on super-resolution localization microscopy. Appl Opt 2022; 61:3516-3522. [PMID: 36256388 DOI: 10.1364/ao.451561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/24/2022] [Indexed: 06/16/2023]
Abstract
Super-resolution localization microscopy (SRLM) breaks the diffraction limit successfully and improves the resolution of optical imaging systems by nearly an order of magnitude. However, SRLM typically takes several minutes or longer to collect a sufficient number of image frames that are required for reconstructing a final super-resolution image. During this long image acquisition period, system drift should be tightly controlled to ensure the imaging quality; thus, several drift correction methods have been developed. However, it is still unclear whether the performance of these methods is able to ensure sufficient image quality in SRLM. Without a clear answer to this question, it is hard to choose a suitable drift correction method for a specific SRLM experiment. In this paper, we use both theoretical analysis and simulation to investigate the relationship among drift correction precision, localization precision, and position estimation precision. We propose a concept of relative localization precision for evaluating the effect of drift correction on imaging resolution, which would help to select an appropriate drift correction method for a specific experiment.
Collapse
|
3
|
Kamboj S, Harms C, Wright D, Nash A, Kumar L, Klein-Seetharaman J, Sarkar SK. Identification of allosteric fingerprints of alpha-synuclein aggregates in matrix metalloprotease-1 and substrate-specific virtual screening with single molecule insights. Sci Rep 2022; 12:5764. [PMID: 35388085 PMCID: PMC8987064 DOI: 10.1038/s41598-022-09866-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/24/2022] [Indexed: 11/16/2022] Open
Abstract
Alpha-synuclein (aSyn) has implications in pathological protein aggregations in neurodegeneration. Matrix metalloproteases (MMPs) are broad-spectrum proteases and cleave aSyn, leading to aggregation. Previous reports showed that allosteric communications between the two domains of MMP1 on collagen fibril and fibrin depend on substrates, activity, and ligands. This paper reports quantification of allostery using single molecule measurements of MMP1 dynamics on aSyn-induced aggregates by calculating Forster Resonance Energy Transfer (FRET) between two dyes attached to the catalytic and hemopexin domains of MMP1. The two domains of MMP1 prefer open conformations that are inhibited by a single point mutation E219Q of MMP1 and tetracycline, an MMP inhibitor. A two-state Poisson process describes the interdomain dynamics, where the two states and kinetic rates of interconversion between them are obtained from histograms and autocorrelations of FRET values. Since a crystal structure of aSyn-bound MMP1 is unavailable, binding poses were predicted by molecular docking of MMP1 with aSyn using ClusPro. MMP1 dynamics were simulated using predicted binding poses and compared with the experimental interdomain dynamics to identify an appropriate pose. The selected aSyn-MMP1 binding pose near aSyn residue K45 was simulated and analyzed to define conformational changes at the catalytic site. Allosteric residues in aSyn-bound MMP1 exhibiting strong correlations with the catalytic motif residues were compared with allosteric residues in free MMP1, and aSyn-specific residues were identified. The allosteric residues in aSyn-bound MMP1 are K281, T283, G292, G327, L328, E329, R337, F343, G345, N346, Y348, G353, Q354, D363, Y365, S366, S367, F368, P371, R372, V374, K375, A379, F391, A394, R399, M414, F419, V426, and C466. Shannon entropy was defined to quantify MMP1 dynamics. Virtual screening was performed against a site on selected aSyn-MMP1 binding poses, which showed that lead molecules differ between free MMP1 and substrate-bound MMP1. Also, identifying aSyn-specific allosteric residues in MMP1 enabled further selection of lead molecules. In other words, virtual screening needs to take substrates into account for potential substrate-specific control of MMP1 activity in the future. Molecular understanding of interactions between MMP1 and aSyn-induced aggregates may open up the possibility of degrading aggregates by targeting MMPs.
Collapse
Affiliation(s)
- Sumaer Kamboj
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Chase Harms
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Derek Wright
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Anthony Nash
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Lokender Kumar
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | | | - Susanta K Sarkar
- Department of Physics, Colorado School of Mines, Golden, CO, USA.
| |
Collapse
|
4
|
Pelicci S, Furia L, Scanarini M, Pelicci PG, Lanzanò L, Faretta M. Novel Tools to Measure Single Molecules Colocalization in Fluorescence Nanoscopy by Image Cross Correlation Spectroscopy. Nanomaterials 2022; 12:686. [PMID: 35215014 PMCID: PMC8875509 DOI: 10.3390/nano12040686] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 01/27/2023]
Abstract
Super Resolution Microscopy revolutionized the approach to the study of molecular interactions by providing new quantitative tools to describe the scale below 100 nanometers. Single Molecule Localization Microscopy (SMLM) reaches a spatial resolution less than 50 nm with a precision in calculating molecule coordinates between 10 and 20 nanometers. However new procedures are required to analyze data from the list of molecular coordinates created by SMLM. We propose new tools based on Image Cross Correlation Spectroscopy (ICCS) to quantify the colocalization of fluorescent signals at single molecule level. These analysis procedures have been inserted into an experimental pipeline to optimize the produced results. We show that Fluorescent NanoDiamonds targeted to an intracellular compartment can be employed (i) to correct spatial drift to maximize the localization precision and (ii) to register confocal and SMLM images in correlative multiresolution, multimodal imaging. We validated the ICCS based approach on defined biological control samples and showed its ability to quantitatively map area of interactions inside the cell. The produced results show that the ICCS analysis is an efficient tool to measure relative spatial distribution of different molecular species at the nanoscale.
Collapse
|
5
|
Žurauskas M, Alex A, Park J, Hood SR, Boppart SA. Fluorescent nanodiamonds for characterization of nonlinear microscopy systems. Photonics Res 2021; 9:2309-2318. [PMID: 37181134 PMCID: PMC10174270 DOI: 10.1364/prj.434236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Characterizing the performance of fluorescence microscopy and nonlinear imaging systems is an essential step required for imaging system optimization and quality control during longitudinal experiments. Emerging multimodal nonlinear imaging techniques require a new generation of microscopy calibration targets that are not susceptible to bleaching and can provide a contrast across the multiple modalities. Here, we present a nanodiamond-based calibration target for microscopy, designed for facilitating reproducible measurements at the object plane. The target is designed to support day-to-day instrumentation development efforts in microscopy laboratories. The images of a phantom contain information about the imaging performance of a microscopy system across multiple spectral windows and modalities. Since fluorescent nanodiamonds are not prone to bleaching, the proposed imaging target can serve as a standard, shelf-stable sample to provide rapid reference measurements for ensuring consistent performance of microscopy systems in microscopy laboratories and imaging facilities.
Collapse
Affiliation(s)
- Mantas Žurauskas
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Aneesh Alex
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- GlaxoSmithKline, Collegeville, Pennsylvania 19426, USA
| | - Jaena Park
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Steve R. Hood
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- GlaxoSmithKline, Stevenage, Hertfordshire SG1 2NY, UK
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Corresponding author:
| |
Collapse
|
6
|
Shang M, Zhou Z, Kuang W, Wang Y, Xin B, Huang ZL. High-precision 3D drift correction with differential phase contrast images. Opt Express 2021; 29:34641-34655. [PMID: 34809249 DOI: 10.1364/oe.438160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Single molecule localization microscopy (SMLM) usually requires long image acquisition time at the order of minutes and thus suffers from sample drift, which deteriorates image quality. A drift estimation method with high precision is typically used in SMLM, which can be further combined with a drift compensation device to enable active microscope stabilization. Among all the reported methods, the drift estimation method based on bright-field image correlation requires no extra sample preparation or complicated modification to the imaging setup. However, the performance of this method is limited by the contrast of bright-field images, especially for the structures without sufficient features. In this paper, we proposed to use differential phase contrast (DPC) microscopy to enhance the image contrast and presented a 3D drift correction method with higher precision and robustness. This DPC-based drift correction method is suitable even for biological samples without clear morphological features. We demonstrated that this method can achieve a correction precision of < 6 nm in both the lateral direction and axial direction. Using SMLM imaging of microtubules, we verified that this method provides a comparable drift estimation performance as redundant cross-correlation.
Collapse
|
7
|
Abstract
Single-molecule localization microscopy techniques transcend the diffraction limit of visible light by localizing isolated emitters sampled stochastically. This time-lapse imaging necessitates long acquisition times, over which sample drift can become large relative to the localization precision. Here, we present an efficient and robust method for estimating drift, using a simple peak-finding algorithm based on mean shifts that is effective for single-molecule localization microscopy in two or three dimensions.
Collapse
|
8
|
Kumar L, Planas-Iglesias J, Harms C, Kamboj S, Wright D, Klein-Seetharaman J, Sarkar SK. Activity-dependent interdomain dynamics of matrix metalloprotease-1 on fibrin. Sci Rep 2020; 10:20615. [PMID: 33244162 PMCID: PMC7692495 DOI: 10.1038/s41598-020-77699-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 11/13/2020] [Indexed: 01/18/2023] Open
Abstract
The roles of protein conformational dynamics and allostery in function are well-known. However, the roles that interdomain dynamics have in function are not entirely understood. We used matrix metalloprotease-1 (MMP1) as a model system to study the relationship between interdomain dynamics and activity because MMP1 has diverse substrates. Here we focus on fibrin, the primary component of a blood clot. Water-soluble fibrinogen, following cleavage by thrombin, self-polymerize to form water-insoluble fibrin. We studied the interdomain dynamics of MMP1 on fibrin without crosslinks using single-molecule Forster Resonance Energy Transfer (smFRET). We observed that the distance between the catalytic and hemopexin domains of MMP1 increases or decreases as the MMP1 activity increases or decreases, respectively. We modulated the activity using (1) an active site mutant (E219Q) of MMP1, (2) MMP9, another member of the MMP family that increases the activity of MMP1, and (3) tetracycline, an inhibitor of MMP1. We fitted the histograms of smFRET values to a sum of two Gaussians and the autocorrelations to an exponential and power law. We modeled the dynamics as a two-state Poisson process and calculated the kinetic rates from the histograms and autocorrelations. Activity-dependent interdomain dynamics may enable allosteric control of the MMP1 function.
Collapse
Affiliation(s)
- Lokender Kumar
- Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Joan Planas-Iglesias
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
- Loschmidt Laboratories, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00, Brno, Czech Republic
| | - Chase Harms
- Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Sumaer Kamboj
- Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Derek Wright
- Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Judith Klein-Seetharaman
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
- Department of Chemistry, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Susanta K Sarkar
- Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA.
| |
Collapse
|
9
|
Kumar L, Nash A, Harms C, Planas-Iglesias J, Wright D, Klein-Seetharaman J, Sarkar SK. Allosteric Communications between Domains Modulate the Activity of Matrix Metalloprotease-1. Biophys J 2020; 119:360-374. [PMID: 32585130 PMCID: PMC7376139 DOI: 10.1016/j.bpj.2020.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 05/30/2020] [Accepted: 06/09/2020] [Indexed: 11/23/2022] Open
Abstract
An understanding of the structure-dynamics relationship is essential for understanding how a protein works. Prior research has shown that the activity of a protein correlates with intradomain dynamics occurring at picosecond to millisecond timescales. However, the correlation between interdomain dynamics and the function of a protein is poorly understood. Here, we show that communications between the catalytic and hemopexin domains of matrix metalloprotease-1 (MMP1) on type 1 collagen fibrils correlate with its activity. Using single-molecule Förster resonance energy transfer, we identified functionally relevant open conformations in which the two MMP1 domains are well separated, which were significantly absent for catalytically inactive point mutant (E219Q) of MMP1 and could be modulated by an inhibitor or an enhancer of activity. The observed relevance of open conformations resolves the debate about the roles of open and closed MMP1 structures in function. We fitted the histograms of single-molecule Förster resonance energy transfer values to a sum of two Gaussians and the autocorrelations to an exponential and power law. We used a two-state Poisson process to describe the dynamics and calculate the kinetic rates from the fit parameters. All-atom and coarse-grained simulations reproduced some of the experimental features and revealed substrate-dependent MMP1 dynamics. Our results suggest that an interdomain separation facilitates opening up the catalytic pocket so that the collagen chains come closer to the MMP1 active site. Coordination of functional conformations at different parts of MMP1 occurs via allosteric communications that can take place via interactions mediated by collagen even if the linker between the domains is absent. Modeling dynamics as a Poisson process enables connecting the picosecond timescales of molecular dynamics simulations with the millisecond timescales of single-molecule measurements. Water-soluble MMP1 interacting with water-insoluble collagen fibrils poses challenges for biochemical studies that the single-molecule tracking can overcome for other insoluble substrates. Interdomain communications are likely important for multidomain proteins.
Collapse
Affiliation(s)
- Lokender Kumar
- Department of Physics, Colorado School of Mines, Golden, Colorado
| | - Anthony Nash
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Chase Harms
- Department of Physics, Colorado School of Mines, Golden, Colorado
| | - Joan Planas-Iglesias
- Warwick Medical School, University of Warwick, Coventry, United Kingdom; Loschmidt Laboratories, Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Derek Wright
- Department of Physics, Colorado School of Mines, Golden, Colorado
| | - Judith Klein-Seetharaman
- Warwick Medical School, University of Warwick, Coventry, United Kingdom; Department of Chemistry, Colorado School of Mines, Golden, Colorado
| | - Susanta K Sarkar
- Department of Physics, Colorado School of Mines, Golden, Colorado.
| |
Collapse
|
10
|
Gao J, Wo X, Wang Y, Li M, Zhou C, Wang W. Postrecording Pixel-Reconstruction Approach for Correcting the Lateral Drifts in Surface Plasmon Resonance Microscope. Anal Chem 2019; 91:13620-13626. [PMID: 31612709 DOI: 10.1021/acs.analchem.9b02804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Surface plasmon resonance microscope (SPRM) sample stage inevitably suffers from lateral drifts as a result of many environmental factors including thermal fluctuation, mechanical vibration, and relaxation. It places great obstacles to time-lapsed imaging and measurements that need high spatial resolution or long recording time. Existing solutions often require experimental efforts such as the addition of optical markers together with piezoelectric stage-based active feedback configurations. Herein, we propose an all-digital, postrecording image-processing method to remove the lateral drift in a series of time-lapsed SPRM images. The method first calculates the value of lateral drift at subpixel accuracy by combining image cross-correlation analysis and superlocalization strategy. It subsequently reconstructed the drift-free image sequences in a pixel-by-pixel and frame-by-frame manner, according to the linear decomposition and reconstruction principle. This method purely relies on image processing, and it does not require any experimental efforts or hardware. In addition to SPRM, we further demonstrated the applicability of the present method in other types of optical imaging techniques including bright-field transmission microscope and dark-field scattering microscope.
Collapse
Affiliation(s)
- Jia Gao
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| | - Xiang Wo
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| | - Yongjie Wang
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| | - Minghe Li
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| | - Chunyuan Zhou
- Nikon Instruments (Shanghai) Co., Ltd. , Shanghai 200120 , P. R. China
| | - Wei Wang
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| |
Collapse
|
11
|
Abstract
The field of fluorescent nanodiamonds (FNDs) has advanced greatly over the past few years. Though historically limited primarily to red fluorescence, the wavelengths available for nanodiamonds have increased due to continuous technical advancement. This Review summarizes the strides made in the synthesis, functionalization, and application of FNDs to bioimaging. Highlights range from super-resolution microscopy, through cellular and whole animal imaging, up to constantly emerging fields including sensing and hyperpolarized magnetic resonance imaging.
Collapse
Affiliation(s)
- Marco D. Torelli
- Adámas Nanotechnologies, Inc., 8100 Brownleigh Dr, Suite 120, Raleigh, NC 27617
| | - Nicholas A. Nunn
- Adámas Nanotechnologies, Inc., 8100 Brownleigh Dr, Suite 120, Raleigh, NC 27617
| | - Olga A. Shenderova
- Adámas Nanotechnologies, Inc., 8100 Brownleigh Dr, Suite 120, Raleigh, NC 27617
| |
Collapse
|
12
|
Copeland CR, Geist J, McGray CD, Aksyuk VA, Liddle JA, Ilic BR, Stavis SM. Subnanometer localization accuracy in widefield optical microscopy. Light Sci Appl 2018; 7:31. [PMID: 30839614 PMCID: PMC6107003 DOI: 10.1038/s41377-018-0031-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 04/24/2018] [Accepted: 05/01/2018] [Indexed: 05/16/2023]
Abstract
The common assumption that precision is the limit of accuracy in localization microscopy and the typical absence of comprehensive calibration of optical microscopes lead to a widespread issue-overconfidence in measurement results with nanoscale statistical uncertainties that can be invalid due to microscale systematic errors. In this article, we report a comprehensive solution to this underappreciated problem. We develop arrays of subresolution apertures into the first reference materials that enable localization errors approaching the atomic scale across a submillimeter field. We present novel methods for calibrating our microscope system using aperture arrays and develop aberration corrections that reach the precision limit of our reference materials. We correct and register localization data from multiple colors and test different sources of light emission with equal accuracy, indicating the general applicability of our reference materials and calibration methods. In a first application of our new measurement capability, we introduce the concept of critical-dimension localization microscopy, facilitating tests of nanofabrication processes and quality control of aperture arrays. In a second application, we apply these stable reference materials to answer open questions about the apparent instability of fluorescent nanoparticles that commonly serve as fiducial markers. Our study establishes a foundation for subnanometer localization accuracy in widefield optical microscopy.
Collapse
Affiliation(s)
- Craig R. Copeland
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
- Maryland NanoCenter, University of Maryland, College Park, MD 20742 USA
| | - Jon Geist
- Engineering Physics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - Craig D. McGray
- Engineering Physics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - Vladimir A. Aksyuk
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - J. Alexander Liddle
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - B. Robert Ilic
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - Samuel M. Stavis
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| |
Collapse
|
13
|
Youn Y, Ishitsuka Y, Jin C, Selvin PR. Thermal nanoimprint lithography for drift correction in super-resolution fluorescence microscopy. Opt Express 2018; 26:1670-1680. [PMID: 29402038 PMCID: PMC5901072 DOI: 10.1364/oe.26.001670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Localization-based super-resolution microscopy enables imaging of biological structures with sub-diffraction-limited accuracy, but generally requires extended acquisition time. Consequently, stage drift often limits the spatial precision. Previously, we reported a simple method to correct for this by creating an array of 1 μm3 fiducial markers, every ~8 μm, on the coverslip, using UV-nanoimprint lithography (UV-NIL). While this allowed reliable and accurate 3D drift correction, it suffered high autofluorescence background with shorter wavelength illumination, unstable adsorption to the substrate glass surface, and suboptimal biocompatibility. Here, we present an improved fiducial micro-pattern prepared by thermal nanoimprint lithography (T-NIL). The new pattern is made of a thermal plastic material with low fluorescence backgrounds across the wide excitation range, particularly in the blue-region; robust structural stability under cell culturing condition; and a high bio-compatibility in terms of cell viability and adhesion. We demonstrate drift precision to 1.5 nm for lateral (x, y) and 6.1 nm axial (z) axes every 0.2 seconds for a total of 1 min long image acquisition. As a proof of principle, we acquired 4-color wide-field fluorescence images of live mammalian cells; we also acquired super-resolution images of fixed hippocampal neurons, and super-resolution images of live glutamate receptors and postsynaptic density proteins.
Collapse
Affiliation(s)
- Yeoan Youn
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- These authors contributed equally to this work
| | - Yuji Ishitsuka
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- These authors contributed equally to this work
| | - Chaoyi Jin
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Paul R. Selvin
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| |
Collapse
|