Western blotting, also known as immunoblotting, is a technique for detecting proteins. Used since the 1970s, it has become an industry standard for protein detection and characterization. It allows researchers to verify the expression of a specific protein, determine the relative amount of protein present and analyze protein-protein interaction.

Western blotting relies on a handful of steps and processes prior to detection. Macromolecules first need to be separated by gel electrophoresis. The proteins are then transferred from the gel to a membrane through which antibodies are used to bind to specific proteins. A substrate is used to attach to the antibodies, which together emit chemiluminescent light for detection.

Traditional western blotting is a labor intensive process. Gel electrophoresis and blotting can take hours to run. The numerous steps may introduce variables that make it difficult to obtain a successful and reproducible blot.

In an effort to optimize this protocol, there have been many advances in technology. In particular, many of the processes have been automated. ProteinSimple, which was acquired by Bio-Techne in 2014 (see IBO 6/30/14), has automated the western blot with its Simple Western Systems. Fully automated, the Systems eliminate the need to manually run a gel or blot because a Simple Western is performed entirely within a capillary. Protein samples, antibodies and reagents are each loaded into a capillary, proteins are separated and an immunoassay is performed, followed by a chemiluminescent substrate. The systems can separate proteins by size or charge, and can perform up to 96 simple westerns in one run. The systems reduce the researcher involvement to two tasks: loading a protein sample into a well plate and looking at the photos.

Thermo Fisher Scientific has decreased the blot procedure time from about 2 hours to 7 minutes with the iBlot 2 Dry Blotting system, which decreases the number of necessary steps. The system also eliminates the need for buffers. The LI-COR Odyssey imaging system uses fluorescence detection instead of chemiluminescence. Although fluorescence has yet to become popular, the digital images are clearer and more reproducible than the images produced on film, according to the company. One scan with the Odyssey CLx Fluorescence system takes six minutes.

Bio-Rad Laboratories offers the V3 Western Workflow, which allows one to visualize, verify and validate electrophoresis and blot quality quickly. This stain-free system has streamlined the blotting process by allowing users to check the progress of a blot, and by reducing gel speeds and blotting speeds to 15 minutes and 3–7 minutes, respectively. Zephyrus Biosciences’ Z1 System is a single-cell western blotting tool. With this system, an individual cell can be lysed and assessed.

The total annual market for automated and semiautomated western blotting systems is nearly $200 million.

Automation of Western Blotting at a Glance:

Leading Suppliers

• Bio-Rad Laboratories

• Thermo Fisher Scientific

• GE Healthcare Life Sciences

Largest Markets

• Academia/Govt.

• Biotech/Pharmaceutical

• CROs

Instrument Cost

• $1,500—$110,000