Contact & Support

Contrast Method

RSS feed
  • The Fundamentals and History of Fluorescence and Quantum Dots

    At some point in your research and science career, you will no doubt come across fluorescence microscopy. This ubiquitous technique has transformed the way in which microscopists can image, tag and trace anything from whole organisms to single proteins and beyond. In this article, we will examine what is meant by "fluorescence", the history and basic physics behind its definition, the discovery and application of Green Fluorescent Protein (GFP) and a look at the rapidly expanding field of fluorescent probes including Quantum Dots.
    Read article
  • Introduction to Widefield Microscopy

    One of the most basic microscopy techniques is known as ‘Widefield Microscopy’. It is fundamentally any technique in which the entire specimen of interest is exposed to the light source with the resulting image being viewed either by the observer or a camera (which can also be attached to a computer monitor).
    Read article
  • Free Webinar On-Demand: Analyze grain size on microstructures the way you need

    Grain size plays an essential role in the mechanical properties of materials. Learn how to overcome problems in sample preparation and how to analyze different materials like, steel, aluminium, titanium, copper and ceramics.
    Read article
  • Digital Microscopy with Versatile Illumination and Various Contrast Methods for More Efficient Inspection and Quality Control

    State-of-the-art digital microscopes utilizing a versatile illumination system capable of achieving multiple contrast methods, such as the Leica DVM6, are very useful for inspection, quality control, and failure analysis. These contrast methods allow flaws or defects on the surface of a product or component to be more easily and rapidly detected.
    Read article
  • Factors to Consider When Selecting a Research Microscope

    An optical microscope is often one of the central devices in a life-science research lab. It can be used for various applications which shed light on many scientific questions. Thereby the configuration and features of the microscope are crucial for its application coverage, ranging from brightfield through fluorescence microscopy to live-cell imaging. This article provides a brief overview of the relevant microscope features and wraps up the key questions one should consider when selecting a research microscope.
    Read article
  • Infinity Optical Systems

    “Infinity Optics” refers to the concept of a beam path with parallel rays between the objective and the tube lens of a microscope. Flat optical components can be brought into this “Infinity Space” without influencing image formation, which is critical for the utilization of contrast methods such as DIC or fluorescence. Modern microscopy techniques require the addition of multiple optical instruments, such as light sources or laser devices, into the infinite light path. Different approaches to fulfill this need have emerged and are described here.
    Read article
  • Glycerol Spraying/Platinum Low Angle Rotary Shadowing of DNA with the Leica EM ACE600 e-beam

    Glycerol spraying/low angle rotary shadowing (Aebi and Baschong, 2006) is a preparation technique used in biology to visualize structures yielding insufficent contrast with other techniques, due to their small diameter. This method is commonly used for specimens which include proteins with coiled coil domains or DNA.
    Read article
  • Step by Step Guide to Fluorescence Microscopy

    Fluorescence Microscopy is a special form of light microscopy. It uses fluorescence to highlight structures in fixed and living biological specimens instead of using absorption, phase or interference effects. The fluorescence is delivered either by inorganic dyes, proteins, synthetic beads or by autofluorescent structures within a sample. In this tutorial the principles of fluorescence microscopy will be explained.
    Read article
  • The Principles of Polarization Contrast

    Polarization contrast microscopy is a convenient way to make birefringent crystalline structures like starch grains or cellulose visible without staining. This tutorial will explain the optical elements in the light path and the operating mode of polarization contrast taking the example of an inverted and motorized high-end research light microscope which can be used for transmitted light contrasting methods and fluorescence microscopy.
    Read article
  • The Principles of Modulation Contrast

    Modulation contrast creates 3D-like images of unstained specimens, rendering it the contrasting method of choice for applications like e.g. in vitro fertilization, where DIC is not possible (due to the usage of plastics) or phase contrast does not deliver satisfying results. This tutorial explains the optical elements in the light path and the operating mode of the modulation contrast.
    Read article
  • The Principles of Phase Contrast

    In this tutorial the principle of phase contrast imaging is described taking the example of an inverted research microscope. Additionally, the alignment of the components needed for phase contrast is shown in the interactive part of the tutorial.
    Read article
  • Differential Interference Contrast

    The examination of live unstained biological specimens often suffers from poor contrast and therefore bad visibility of the specimen. Thick specimens in particular, such as brain slices, show up as nothing more than light grey structures instead of single cells. This tutorial explains the optical elements in the light path and the operating mode of DIC (differential interference contrast) on the example of an inverted and motorized high-end research light microscope which can be used for transmitted light contrasting methods and fluorescence microscopy.
    Read article
  • Metallography with Color and Contrast

    The examination of microstructure morphology plays a decisive role in materials science and failure analysis. There are many possibilities of visualizing the real structures of materials in the light microscope. The image samples shown in this article demonstrate the information potential of some of the techniques used.
    Read article
  • Optical Contrast Methods

    Optical contrast methods give the potential to easily examine living and colorless specimens. Different microscopic techniques aim to change phase shifts caused by the interaction of light with the specimen into amplitude shifts that are visible to the human eye as differences in brightness.
    Read article
  • Phase Contrast

    Phase contrast is an optical contrast technique for making unstained phase objects (e.g. flat cells) visible under the light microscope. Cells that appear inconspicuous and transparent in brightfield can be viewed in high contrast and rich detail using phase contrast microscopy.
    Read article
  • Differential Interference Contrast (DIC)

    Differential interference contrast (DIC) microscopy is a good alternative to brightfield microscopy for gaining proper images of unstained specimens that often only provide a weak image in brightfield.
    Read article
  • Integrated Modulation Contrast (IMC)

    Hoffman modulation contrast has established itself as a standard for the observation of unstained, low-contrast biological specimens. The integration of the modulator in the beam path of themodern inverted microscopes allows a wide range of brightfield or phase objectives to be used, rather than a small selection of special objectives.
    Read article
  • An Introduction to Fluorescence

    Fluorescence is widely used in microscopy and an important tool for observing the distribution of specific molecules. Most molecules in cells do not fluoresce. They therefore have to be marked with fluorescing molecules called fluorochromes.
    Read article
  • Polarization Contrast

    Polarization microscopy is routinely applied in material sciences and geology to identify minerals on the basis of characteristic refraction properties and colors. In biology, polarization microscopy is commonly used for identification or imaging of birefringent structures like crystals, or for imaging of cellulose in cell walls of plants and starch grains.
    Read article
  • Fluorescence in Microscopy

    Fluorescence microscopy is a special form of light microscopy. It uses the ability of fluorochromes to emit light after being excited with light of a certain wavelength. Proteins of interest can be marked with such fluorochromes via antibody staining or tagging with fluorescent proteins.
    Read article