The cantilever arm has a shape selected to tune the fundamental resonance frequency or a resonance frequency of a selected higher order mode so that the fundamental and higher order resonance frequencies have an integer ratio or near integer ratio. The outoffocus image degradation problem of oct also puts an impediment to its application to developmental biology studies. The laser beam was scanned in the x and y axes using a pair of galvanometric mirrors cambridge technologies, inc. The nonlinear effect of shg and thg on the imaging properties of confocal microscopy has been analyzed in detail by the imaging theory. In prior work, we showed the utility of second harmonic generation imaging.
Secondharmonic imaging microscopy shim on a laserscanning system proves. However, these optical modalities rely on exogenous labeling. We extend the subtractive imaging method to label free second harmonic generation shg microscopy to enhance the spatial resolution and. It is shown that this method can resolve interfaces and inhomogeneities with axial resolution comparable to the confocal length of the beam. Higher harmonic generation microscopy of in vitro cultured mammal oocytes and embryos. To satisfy the nyquist criterion for both tpm and thg, a pixel size of 0. The nonlinear imaging theory of second harmonic generation shg and third harmonic generation thg in confocal microscopy is presented in this paper. By adapting a laser scanning microscope with a titanium sapphire femtosecond pulsed laser and transmission optics, we are able to produce live cell images based on the nonlinear optical phenomenon of second harmonic generation shg. With increasing applications of multiphoton microscopy to thicktissue intravital imaging, second harmonic generation shg from structural proteins has emerged as a potentially important new contrast mechanism. Tripling the maximum imaging depth with third harmonic generation microscopy murat yildirim,a nicholas durr,b,c and adela benyakara,c, athe university of texas at austin, department of mechanical engineering, 204 east dean keeton street, stop c2200, austin. Fully integrated reflectionmode photoacoustic, twophoton. Higher harmonic generation microscopy springerlink. Second harmonic generation microscopy is a novel technique. Nonlinear scanning laser microscopy by third harmonic generation.
May 01, 2011 second harmonic generation microscopy has emerged as a powerful new optical imaging modality. The extracellular matrix plays an important role in cellular balance, and collagen fibers are its most important component. We present a fast scanning transmissionmode confocal scanning laser microscope system based on the use of a second harmonic generation shg crystal for signal detection. Resolution and contrast enhancement of subtractive second.
The technique could then be a powerful tool in biomedicine andor in clinical diagnoses. The imaging theory of nonlinear second harmonic generation shg and third harmonic generation thg in confocal microscopy is presented in this paper. Secondharmonic generation shg is beginning to emerge as a powerful. Membrane imaging by simultaneous secondharmonic generation and twophoton microscopy l. Second harmonic imaging shim is an ideal method for probing membranes of living cells because it offers the high resolution of nonlinear optical microscopy with. We performed second harmonic generation shg imaging of collagen in rattendon cryosections, using femtosecond laser scanning confocal microscopy, both in backscattering and transmission geometries. Pdf when the energy density at the focal spot of a microscope is.
Shg was first demonstrated by kleinman in crystalline quartz in 1962 kleinman, 1962, and, since that time, has been commonly used to frequency double pulsed lasers to obtain shorter wavelengths. Because of its underlying physical origin, it is highly. Two photon microscopy and second harmonic generation leif gibb and david matthews introduction and background nonlinear microscopy has become an important tool for imaging biological samples such as neurons. Aug 31, 2016 fully integrated reflectionmode photoacoustic, twophoton and second harmonic generation microscopy in vivo. Osa labelfree second harmonic generation holographic. Higher harmonic generation is a nonlinear coherent scattering process. Characterization of oral precancerous lesions based on. Higher harmonic generation microscopy hhgm, based on nonlinear multiphoton excitation, is a contrast mechanism for the structural and molecular imaging of native samples in cell culture and in fixed and live tissues, for both, three.
Virtual optical biopsy of human adipocytes with third. Studying metalorganic frameworks using second harmonic generation microscopy nanowerk news linkam scientific instruments report on the use of their thms600 temperature controlled stage in the study of metalorganic frameworks using second harmonic generation microscopy at the university of leuven. Second harmonic generation microscopy versus third. The onehalf wavelength out of phase, caused by the specimen. Highresolution nonlinear optical imaging of live cells by. A new mode of contrast in biological second harmonic. May 27, 2015 these findings may offer key insights into the biologic underpinnings of refractory versus treatable pulmonary fibroses, and highlight the potential of second harmonic generation microscopy as a novel diagnostic tool for distinguishing between these clinical scenarios. Over the last few years, second harmonic generation shg microscopy. Membrane imaging by simultaneous secondharmonic generation. The use of harmonic generation allows image formation of endogenous features in biological samples such as muscle tissue. Tripling the maximum imaging depth with thirdharmonic. Second harmonic imaging microscopy shim is based on a nonlinear optical effect known as second harmonic generation shg. Add 750 l cellfree collagen stock solution and mix until homogenous slightly.
Here we show that third harmonic generation thg microscopy is a suitable tool for label free intravital investigations of the microcirculation in widelyused physiological model systems. Pdf optimization of secondharmonic generation microscopy. Thg has been applied for labelfree imaging of the brain farrar et al. Estimation of helical angles of myosin and collagen by second. Shim has been established as a viable microscope imaging contrast mechanism for visualization of cell and tissue structure and function. In this study, we combined these two approaches by using acellular dermal matrix adm recellularized with mscs to repair cutaneous wounds in a murine model and twophoton fluorescence tpf microscopy and second harmonic generation shg microscopy to assess the effects of this therapy on wound healing. Request pdf higher harmonic generation microscopy higher harmonic generation, including second harmonic generation and third harmonic generation, leaves no energy deposition to the interacted. Second harmonic imaging microscopy of living cells pdf. This effect was enhanced with the use of an indexmatching fluid ni1.
Secondharmonic generation imaging of membrane potential. Optical second harmonic generation microscopy as a tool of. We use photon counting to improve the sn of weak shg signal detection. Third harmonic generation microscopy of cells and tissue organization. Labelfree second harmonic generation holographic microscopy of. Second harmonic generation shg microscopy has emerged as a powerful modality for imaging fibrillar collagen in a diverse range of tissues. The second harmonic generation microscope shgm constructs images of intensity distributions of sh waves produced by the interaction of fundamental waves with a polar material. Based on digital holography, this technique captures, in singleshot hologram acquisition, both the amplitude and the phase of a coherent shg radiation, which makes possible second harmonic phase microscopy.
Advanced microscopy techniques for revealing molecular. A harmonic cantilever for use in an atomic force microscope includes a cantilever arm and a probe tip. The correlated action of hundreds of sarcomeres is needed to produce the myocyte contractions. Sheppard, second harmonic imaging in the scanning optical microscope, opt.
We have acquired holograms with acquisition times as short as 10 ms, limited by the switching speed of our shutter. Nonlinear optical microscopy by multiphoton excitation has. Not to be confused with twophoton excitation microscopy. Higher harmonicgeneration, including second harmonic generation and third harmonic generation, leaves no energy deposition to the interacted matters due to its virtuallevel transition characteristic, providing a truly noninvasive modality and is ideal for in vivo imaging of live specimens without any preparation. In this study, second harmonic generation shg microscopy is employed for imaging striated myocytes. Pdf simulation of higher harmonics generation in tapping. Pdf higher harmonic generation microscopy of in vitro. Chara plant rhizoids have been imaged, showing dynamic plant activity, and nonfading image characteristics even with continuous viewing, indicating prolonged viability under.
Fully integrated reflectionmode photoacoustic, twophoton and second harmonic generation microscopy in vivo. In this study, we combined these two approaches by using acellular dermal matrix adm recellularized with mscs to repair cutaneous wounds in a murine model and twophoton fluorescence tpf microscopy and second harmonic generation shg microscopy. Excited by a 1230 nm femtosecond laser, thg signals were generated at a significantly higher level in neutrophils than other mononuclear cells, whereas signals in agranular lymphocytes were one order of magnitude smaller. We have recently proposed and demonstrated a novel nonlinear scanning laser microscope that uses third harmonic generation thg to characterize transparent specimen 10. Keywords nonlinear microscopy techniques, second harmonic generation shg imaging microscopy, multiphoton microscopy, breast cancer, ovarian cancer introduction ovarian and breast cancers account for 31% of all cancerassociated deaths each year despite the respective high 5year survival rates of 92% and 99% when diagnosed in early stages. Secondharmonic imaging microscopy shim is based on a nonlinear optical effect known as secondharmonic generation shg. Second harmonic generation microscopy has emerged as a powerful new optical imaging modality. Simultaneous stimulated raman scattering and higher. All these imaging modalities are compatible with twophoton excited. Among all label free optical tomography techniques, third harmonic generation thg microscopy can achieve better contrast and. Labelfree imaging of bone multiscale porosity and interfaces using. With these advanced microscopy techniques 1824, we can characterize the 3d morphology of adipocytes without labeling.
Simulation of higher harmonics generation in tappingmode atomic force microscopy article pdf available in applied physics letters 7926. Higher harmonic generation, including second harmonic generation and third harmonic generation, leaves no energy deposition to the interacted matters due to its virtuallevel transition characteristic, providing a truly noninvasive modality and is ideal for in vivo imaging of live specimens without any preparation. Labelfree second harmonic generation holographic microscopy. It is thus highly desired to apply hgm for in vivo mucosa histopathological diagnosis. Pdf secondthird harmonic generation microscopy researchgate. Optical microscopy davidson and abramowitz 3 degrees out of step more commonly, out of phase with the direct light that has passed through undeviated. Second harmonic generation shg and third harmonic generation thg processes are both nonlinear processes, related to the interaction of intense light with matters. Estimation of helical angles of myosin and collagen by second harmonic generation imaging microscopy franc. Imaging cells and extracellular matrix in vivo by using. Apr 18, 2014 second harmonic generation shg is a novel imaging technology that could provide optical biopsy during endoscopy with advantages over current technology. Fluorescence microscopy has become an essential tool in biology as well as in materials science as it has attributes that are not readily available in other optical microscopy techniques. Osa additivecolor multiharmonic generation microscopy. The use of an array of fluorochromes has made it possible to identify cells and submicroscopic cellular components and entities with a high. In biological tissue, type i and ii fibrillar collagen, microtubule assemblies including centrosomes and mitotic spindles and muscle myosin all endogenously.
Shg has the unique ability to evaluate the amount of extracellular matrix collagen protein and its alignment. Pdf second harmonic generation microscopy for quantitative. Label free imaging techniques, such as coherent antistokes raman scattering microscopy and second harmonic generation microscopy can. Imaging with secondharmonic generation nanoparticles. Second harmonic generation microscopy gets better contrast. Third harmonic generation near the focal point of a tightly focused beam is used to probe microscopical structures of transparent samples. We have previously developed a new way for nonscanning second harmonic generation shg microscopy opt. Because of its underlying physical origin, it is highly sensitive to the collagen fibrilfiber structure, and, importantly, to changes that occur in diseases such as cancer, fibrosis and connective tissue disorders. Enhancing resolution and contrast in secondharmonic. Secondorder nonlinear holographic microscopy for highspeed, threedimensional imaging is demonstrated. Higher harmonic generation microscope hgm, providing images with a higher harmonic generation microscopy hgm can provide a noninvasive biopsy tool with excellent 3d spatial resolution because of its virtual transition and nonlinear characteristics. Recent clinical studies on human skin indicated that in vivo multi harmonic generation microscopy hgm can achieve submicron resolution for histopathological analysis with a high penetration depth and leave no energy or photodamages in the interacted tissues. Characterization of muscle contraction with second harmonic.
The nonlinear imaging theory of second harmonic and third. Shg signal originates from two excitation photons which interact with the material and are reconverted to form a new emitted photon with half of wavelength. Structure sensitivity in thirdharmonic generation microscopy. The design and construction of a second harmonic generation. The fibrillar collagen in sinusoids of normal livers could be observed through second harmonic generation shg microscopy. Zhilie tang, da xing, and songhao liu the nonlinear imaging theory of second harmonic and third harmonic generations in confocal microscopy. In vivo optical virtual biopsy of human oral mucosa with. Labelfree secondharmonic phase imaging of biological. Raman scattering cars, secondharmonic generation shg or thirdharmonic generation thg are receiving considerable attention.
Labelfree live brain imaging using thirdharmonic generation microscopy. Second harmonic generation shg, also called frequency doubling is a nonlinear optical process in which two photons with the same frequency interact with a nonlinear material, are combined, and generate a new photon with twice the energy of the initial photons equivalently, twice the frequency and half the wavelength, that conserves the coherence of the excitation. Least invasive in vivo imaging using harmonic generation. This work is a major step towards labelfree microscopic live brain imaging, and opens up. We have developed this nonlinear optical microscope in order to make possible nondestructive, threedimensional 3d observations of various kinds of inorganic and organic materials. New harmonic generation microscopy techniques based on focal. Commonly used methods, histological staining followed by either semiquantitative or computerized image analysis, have limited sensitivity, accuracy, and operatordependent variations. Photonics dictionary secondharmonic generation microscopy a nonlinear label free imaging technique commonly used during surgical procedures for the visualization of collagen fibers and muscle tissue myosin with submillimeter resolution. A new mode of contrast in biological second harmonic generation microscopy. Previous studies have shown that harmonic generation microscopy hgm, a virtual. Secondharmonic generation shg microscopy is a label free imaging technique to study collagenous materials in extracellular matrix environment with high resolution and contrast. Secondharmonic generation microscopy for assessment of. Starch is a major source of our daily diet and it is important to understand the molecular structure that plays a significant role in its wide number of applications.
Most multiphoton microscopy studies in biological systems have relied on twophoton excited fluorescence tpef to produce images. Read simultaneous stimulated raman scattering and higher harmonic generation imaging for liver disease diagnosis without labeling, proceedings of spie on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Matcher2,3 enhanced image contrast in biological second harmonic imaging microscopy shim has previously. A second harmonic microscope obtains contrasts from variations in a specimens ability to generate second harmonic light from the.
Shg transmission images of collagen fibers were spatially resolved due to a coherent, directional shg component. Excited by a 1230 nm femtosecond laser, thg signals were generated at a significantly higher level in neutrophils than other mononuclear cells, whereas signals in agranular lymphocytes were one order of. Jan 14, 2014 the framework is the first to include reflection and refraction of the excitation beam and nonlinear signals by an arbitrary number of interfaces in the focal volume, which is especially significant for the interpretation of third harmonic generation thg. Threedimensional highresolution secondharmonic generation. Osa second harmonic generation microscopy of early. This resolving power is good enough for cellular imaging but still inferior to that of nonlinear microscopies including multiphoton fluorescence microscopy and higher harmonic generation microscopy. In these microscopies, the signal is a coherent superposition of the. Hematoxylin and eosinstained slides from colon biopsies normal, lowgrade dysplasia lgd, highgrade dysplasia hgd, and. Laser scanning thirdharmonicgeneration microscopy in biology.
Additivecolor multi harmonic generation microscopy for simultaneous label free differentiation of plaques, tangles, and. Third harmonic generation microscopy is used to make dynamical images of living systems for the first time. Us7451638b1 harmonic cantilevers and imaging methods for. Because of its underlying physical origin, it is highly sensitive to the collagen fibrilfiber structure, and. This study probes the molecular structure of the myofilaments and investigates the movement correlations between sarcomeres during contraction. Higher harmonic generation microscopy for developmental biology. Imaging granularity of leukocytes with third harmonic. Labelfree determination of hemodynamic parameters in the. Multiphoton microscopy and second harmonic generation loci. Using third harmonic generation thg microscopy, we demonstrate that granularity differences of leukocytes can be revealed without a label. A study on image quality in polarizationresolved second harmonic generation microscopy. Second harmonic generation nanoparticles show promise as imaging probes due to their coherent and stable signal with a broad flexibility in the choice of excitation wave. Second harmonic generation shg is beginning to emerge as a powerful contrast mechanism in nonlinear optical microscopy.
Second harmonic generation shg can be used for imaging membrane potential in neurons, but poor signaltonoise snlimits accurate measurements of small voltage transients. Pdf in vivo imaging using harmonic generation microscopy. Second harmonic generation microscopy for quantitative. Higher harmonic generation microscopy for developmental. In two photon fluorescence, a fluorophore absorbs two photons at a low. Higher collagen signals are observed in breast fibroadenomas in comparison to. In this work, we present holographic shg phase microscopy. Second harmonic generation confocal microscopy of collagen. Second harmonic generation microscopy reveals altered.
Two photon microscopy and second harmonic generation. Here, we demonstrate, for the first time, a label free additivecolor multi harmonic generation microscopy to elucidate, concurrently with different hues, alzheimers disease ad neuropathological hallmarks. Thirdharmonic generation microscopy with focusengineered. Second harmonic generation shg microscopy uses samefrequency photons that interact with a noncentrosymmetric material and are combined to form new photons with twice the energy. Studying metalorganic frameworks using second harmonic. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals. The extracellular matrix ecm, and particularly fibrillar collagen, are central to heart biomechanics, regulating tissue strength, elasticity and contractility. Second harmonic generation microscopy is a label free optical imaging technology which can detect and quantitate collagen in tissue sections without immunostaining. In vivo imaging using harmonic generation microscopy. This feature describes its chemical and physical principles and highlights current applications in disease diagnostics. Higher harmonic generation microscopy for developmental biology chikuang sun,a, shiwei chu,a szuyu chen,a tsunghan tsai,a tzuming liu,a chungyung lin,b and huaijen tsaib a graduate institute of electrooptical engineering and department of electrical engineering, national taiwan university, taipei 10617, taiwan, roc b institute of molecular and cell biology, national taiwan university. Labelfree live brain imaging and targeted patching with third. Second harmonic generation microscopy versus third harmonic generation microscopy in biological tissues. The quadratic intensity dependence of shg is exploited to preferentially reveal unscattered signal light and reject outoffocus scattered background.
Here, we explore second harmonic generation shg microscopy for visualization of establishing cardiac fibers such as collagen in mouse embryos through the earliest stages of development. Nonlinear microscopy presents numerous advantages over linear microscopy techniques including improved deep tissue. Determination of blood flow velocity and related hemodynamic parameters is an important aspect of physiological studies which in many settings requires fluorescent labeling. Read higher harmonic generation microscopy for developmental biology, journal of structural biology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. It is proved that the imaging process of shg and thg in confocal microscopy, which is different from. Imaging of biological membranes in liquid institute for biophysics johannes kepler university of linz altenbergerstr. Second harmonic generation imaging distinguishes both high.