Protein Chip

A protein chip (or protein microarray) is a high-throughput method used to track the interactions and activities of proteins and to determine their function. It is a miniaturized and parallel assay system that contains small amounts of purified proteins in a high-density format. The main advantage of this technique is that large numbers of proteins can be tracked in parallel.

There are mainly three types of protein chips according to their application--analytical microarrays, functional microarrays, and reverse-phase microarrays. The difference lies in the protein set on the chip. Analytical chips consist of capture molecules such as antibodies with high specificity to the target protein, usually used to detect the protein quantity in different solutions. Immobilizing purified protein with the natural structure on the substrate, functional chips are used to identify the interaction of protein-protein, protein-DNA, and protein-small molecules. Reverse-phase chips contain complex samples such as cell lysate, to determine if the alternation of protein caused by disease exists. In the past few years, protein microarray technology has shown its great potential in basic research, diagnostics, and drug discovery.

Fig.1 Different types of protein chips.

The detection of protein chips is mainly based on the specific non-covalent binding of antigens and antibodies. A large number of different protein molecules are ordered on the surface of the solid phase carrier in the form of a microarray. So, when the fluoro-labeled protein binds with the chip specifically, the information about the protein to be tested can be obtained by detecting the fluorescence signal.

• Selection and handling of substrate material
  A variety of materials can be chosen for substrate, such as glass slides, PDMS, silicon, etc. The substrate material should be pretreated in proper ways depending on the type. The ways of immobilizing protein molecules include adsorption, covalent bonding, molecular self-assembly, etc.
• Immobilizing proteins onto the substrate
  Immobilize proteins onto the substrate using a standard contact spotter or noncontact microarrayer.

• Extraction and purification of protein
  Protein extraction is the process of isolating and purifying the protein from samples of whole tissue, cell cultures, or biological fluids, to provide sufficient materials for the follow-up operation.
• Labeling of protein
  The protein to be detected is commonly labeled by fluorescent molecules. Different protein samples can be labeled with different colors for better analysis. Common fluorescent markers include cy3 and cy5. Other labels like affinity, photochemical, or radioisotope tags can also be chosen, they may lead to unsatisfied results since these labels are attached to the probe itself and influence the probe-target interaction.
• Hybridization with protein chip
  Incubate protein to be detected with protein chips together, allowing them to bind through by antigen-antibody specific reaction.
• Scanning and analysis of results
  Fluorescence is excited at a specific wavelength by a confocal fluorescence scanner or a CCD fluorescence imager, and the signal of specific binding is obtained.

• Micro-quantification: consuming small quantities of samples and reagent
• High-throughput: parallel analysis of thousands of target protein
• High signal-to-noise ratio, high accuracy, and high sensitivity
• Rapid, automated and economical
• Able to perform quantitative detection by standard curve

• Analysis of protein binding properties
• Monoclonal antibody specificity profiling
• Analysis of protein post-translational modifications
• Treatment development
• Research on host-microbe interactions
• Biomarker identification

Microarray Slides

Microarray slides facilitate the closure of a large number of tissue samples for use in a microarray system. Slide dimensions for both DNA and protein arrays are compatible with a variety of microarrayers and scanners. A variety of surface treatments are available to suit your research purpose.

Microplate Handling

Microplate handling is a kind of automated devices and systems designed to manipulate microplates, that can be integrated with a variety of laboratory equipment. Products include microplate stackers, dispensers, media exchangers, etc.

Pipettes

A pipette is a laboratory tool commonly used in chemistry, biology and medicine to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes.

Automated Liquid Handling Systems

Automated liquid handling systems dispense and sample liquids in tubes or wells and are often integrated as automated injection modules as the front end of liquid chromatographic systems. These critical labor-saving devices offer precision sample preparation for high throughput screening/sequencing (HTC), liquid or powder weighing, sample preparation, and bio-assays of many kinds.

DNA/RNA/Protein Purification Systems

DNA/RNA/Protein Purification System is a compact automated nucleic acid extraction and purification platform that can process up to several samples simultaneously. The instrument can purify DNA or RNA from various sample types in the same consistent and reliable manner with higher throughput.

Slide Hybridization Systems

The programmable slide hybridization system offers researchers a compact muti-position Slide Hybridization system capable of performing complex IHC and In Situ Hybridization reactions. The digital microprocessor control offers full programmability of up to three time-controlled temperature set points. The precision temperature control and sealed chamber offer the ideal environment for controlled IHC and In Situ Hybridization reactions.

Laboratory Incubators

An incubator is a device used to grow and micro biological cultures or cell cultures. It is made up of a chamber with a regulated temperature. Some incubators also regulate humidity, gas composition, or ventilation within that chamber. An incubator maintains optimal temperature, humidity, and other conditions such as the oxygen content of the atmosphere inside.

Laboratory Rockers and Shakers

A rocker or shaker is a piece of laboratory equipment used to mix, blend, or agitate substances in a tube or flask by shaking them. These important tools are used for a variety of applications including cell culture, DNA extraction, mixing reagents, and staining gels and blots. A shaker contains an oscillating board that is used to place the flasks, beakers, or test tubes.

Centrifuges

A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities. It works by causing denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense are displaced and moved to the center.

Spectrofluorometers

A spectrofluorometer is an instrument that takes advantage of some compounds' fluorescent properties to provide information regarding their concentration and chemical environment in a sample. A specific excitation wavelength is selected, and the emission is observed either at a single wavelength, or a scan is performed to record the intensity versus wavelength, also called an emission spectrum.

Microplate Readers

Microplate readers are essential laboratory instruments, used widely across both industry and academia. Also commonly referred to as plate readers, these analytical instruments allow a steady stream of microplates to be read for the value(s) being measured in the samples. Microplate readers differ mainly by their modes of detection, such as absorbance, fluorescence, or luminescence.

Confocal Laser Scan Microscopes

Confocal Microscopy is an optical imaging technique for increasing the Optical Resolution and Contrast of a Micrograph by using a Spatial Pinhole to block out-of-focus light in image formation. Capturing multiple two-dimensional images at different depths in a specimen enables the reconstruction of three-dimensional imaging.

STEMart provides you with a variety of equipment or consumables used in protein chip techniques to meet your various R&D and application needs. If you have any questions or requirements for protein chips, please feel free to contact us.