Proteins and Protein Crystals

Protein crystals can be quickly located & identified by UV microscopy.

Proteins are essential parts of living beings and participate in almost every cellular process. They consist of linear chains of amino acids bound to one another.  There are 22 standard or proteinogenic amino acids and a host of others.  The protein is defined by its primary, secondary and tertiary structures.  The primary structure is the sequence of amino acids.  The secondary structures are stabilized repeating local structures, such as alpha helices and beta sheets.  Finally, the tertiary structure is the three dimensional structure of the protein as a whole.

Protein crystals are grown for a number of different reasons. Protein crystallization is used for drug design and for bioseparation.  One of the most important facets is to grow protein crystals so that their tertiary structures canbe studied by x-ray diffraction.

Protein Crystallization

Protein crystallization is a challenging process due to the delicacy of the protein crystal.  It is most commonly done by a vapor diffusion method.  Crystals are induced to form from a droplet of a protein-saline solution.  Water vaporizes from the drop into a reservoir until the concentration of the protein in the drop is high enough for crystallization.  Under the correct conditions, a crystal can then be grown.  Of course, one disadvantage of this technique is that salt crystals can also be grown with the protein crystals.

Problems and Solutions with Protein Crystallization

Besides being very fragile in nature, differentiating protein crystals from the salt crystals that form with them is quite challenging.  To the naked eye or under a common microscope, both appear identical in most cases.  However, there are two optical methods that can be used to differentiate them. 

UV Absorption of Proteins: The fastest and safest method is to separate protein crystals from salt crystals by using a UV microscope or microspectrophotometer.  The protein absorbs light at 280 nm.  The salt crystal does not.  The image and the spectra of the protein crystal are dramatically different from a salt crystal.

Intrinsic Protein Fluorescence: If the protein contains tryptophan, the crystal can be induced to fluoresce albeit weakly while the salt crystal cannot.  This a slower method, however, imaging and spectroscopy can then be used to successfully separate the protein from the salt crystals.  

 UV-visible-NIR microscopes, UV-visible-NIR microspectrometers and Raman microspectrometers are general purpose laboratory instruments. They have not been cleared or approved by the European IVD Directive, the United States Food and Drug Administration or any other agency for diagnostic, clinical or other medical use.

OLED Metrology

OLED

Microspectrophotometers are used to test the color and intensity of each OLED pixel

 

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OLED emission spectra

Typical test spectra from three pixels of an OLED display

 

 

OLED Inspection: Color, relative intensity, spectroscopy and film thickness of OLED pixels and light sources.

The organic light emitting diode, or OLED, is a light emitting diode that utilizes organic compounds to emit light.  The basic OLED is made of an a cathode, an emissive layer, a conductive layer, a substrate and an anode.  Placing a charge across the layers causes the emission of photons from the emissive layer by the process of electrophosphorescence.  Different types of organic molecules and different manufacturing processes result in various colors and display designs. 

Due to the nature of organic light emitting diode devices, they can be manufactured by a printing process that causes rows of microscopic pixels to be deposited on a surface.  Such designs will lead to the common use of OLED devices as displays and light sources.  Because each pixel is its own colored light source, OLED devices use less power and are smaller and lighter than comparable LED displays.  They also have superior black levels.  As such, OLED displays and light sources are in great demand.

Development testing and quality control of both the components and completed OLED devices are done by optical microspectroscopy.  Microspectrometers, such as those made by CRAIC Technologies, are used to measure the spectra and the intensity of the output from individual pixels and from groups of pixels.  They are even used to map the color and intensity outputs of entire displays.  This is important as manufacturers of organic light emitting diodes need to make sure that all the different types of pixels are the same color and brightness.  A microspectrophotometer does this quickly and easily.  

To learn more about microspectroscopy and OLED analysis and testing, select one of the following links: 

What is a Microspectrophotometer?

Science of Microspectrophotometers

Colorimetry of Pixels and Displays

Relative Intensity Measurements

508 FPD™ Spectrophotometers for Microscopes and Probe Stations

 

Nanobiotechnology Instrumentation

Nanobiotechnology development with a microspectrophotometer

Microspectrophotometers are used to analyze nanobiotechnology products by reflectance, absorbance and fluorescence

 

Nanotechnology

Microspectra

 

 

UV-visible-NIR microscopy and microspectroscopy for analysis of nanotechnology.

Nanobiotechnology applies the principles of nanotechnology to biotechnology: where the technological products and organisms are derived from biology and agricultural sciences.  Products resulting from nanobiotechnology research are used in three major areas: agriculture,  biofuels and environmental applications.  As such, nanobiotechnology ranges from microarrays where thousands or millions of tests can be conducted on a single device simultaneously, bioengineering and bioremediation. 

  Able to analyze micro-scale volumes by absorption, reflectance or even fluorescence, microspectrophotometers are easy-to-use and very accurate.  Their flexibility and accuracy make them very important for analyzing everything from genetically engineered organisms to sophisticated microarrays. 

To learn more about microspectroscopy and nanobiotechnology applications, select one of the following links: 

What is a Microspectrophotometer?

Science of Microspectrophotometers

Microspectrophotometer Design

Uses of Microspectrophotometers

20/30 PV™ Microspectrophotometers

 UV-visible-NIR microscopes, UV-visible-NIR microspectrometers and Raman microspectrometers are general purpose laboratory instruments. They have not been cleared or approved by the European IVD Directive, the United States Food and Drug Administration or any other agency for diagnostic, clinical or other medical use.

Microplate Analysis

Microplate analysis with a microspectrophotometer

Microspectrophotometers are used to analyze microplates by reflectance, absorbance and fluorescence

 

Microplate

Microspectra

 

 

UV-visible-NIR microscopy and microspectroscopy for analysis of any microplate test point..

Microplate devices, sometimes called lab-on-a-chip devices, are designed to replicate a series of full-scale chemical and biological reactions on a single micro-scale device.  They are sometimes called microelectromechanical systems (MEMS) for their fluid handling capabilities on the microscopic scale. As such, a single device is used to replicate a series of chemical reactions but on a microscopic scale.  Therefore analytical techniques are required that can measure whether reactions have reached a successful conclusion but of micro-scale volumes.

 Able to analyze micro-scale volumes by absorbance, reflectance or even fluorescence, microspectrophotometers are easy-to-use and very accurate.  Their flexibility and accuracy make them very important when developing or using custom microplates. 

To learn more about microspectroscopy and microplate testing, select one of the following links:

What is a Microspectrophotometer?

Science of Microspectrophotometers

Uses of Microspectrophotometers

20/30 PV™ Microspectrophotometers

 UV-visible-NIR microscopes, UV-visible-NIR microspectrometers and Raman microspectrometers are general purpose laboratory instruments. They have not been cleared or approved by the European IVD Directive, the United States Food and Drug Administration or any other agency for diagnostic, clinical or other medical use.

Microfluidic Device Analysis

Microplate analysis with a microspectrophotometer

Microspectrophotometers are used for microplate analysis by reflectance, absorbance and fluorescence

 

Microplate

Microspectra

 

 

UV-visible-NIR microscopy and microspectroscopy for analysis of any microplate test point..

Microfluidic devices, sometimes called lab-on-a-chip devices, are designed to replicate a series of full-scale chemical and biological reactions on a single micro-scale device.  They are sometimes called microelectromechanical systems (MEMS) for their fluid handling capabilities on the microscopic scale. As such, a single device is used replicate a series of chemical reactions but on a microscopic scale.  Therefore analytical techniques are required that can measure whether reactions have reached a successful conclusion but of micro-scale volumes.

.  Able to analyze micro-scale volumes by absorbance, reflectance or even fluorescence, microspectrophotometers are easy-to-use and very accurate.  Their flexibility and accuracy make them very important when developing or using custom microfluidic devices. 

To learn more about microspectroscopy and microfluidic device development and testing, select one of the following links:

What is a Microspectrophotometer?

Science of Microspectrophotometers

Uses of Microspectrophotometers

20/30 PV™ Microspectrophotometers

UV-visible-NIR microscopes, UV-visible-NIR microspectrometers and Raman microspectrometers are general purpose laboratory instruments. They have not been cleared or approved by the European IVD Directive, the United States Food and Drug Administration or any other agency for diagnostic, clinical or other medical use.