Imaging and Analysis of 2-D Electrophoresis Gels

Image Acquisition Instruments

Analysis of high-quality 2-D gels is a basic requirement for investigating changes in protein expression. Before 2-D gels can be analyzed with an image evaluation system, they must be digitized. The most commonly used devices are camera-based systems, densitometers, phosphor imagers, and fluorescence scanners. Bio-Rad has imaging equipment suitable for different kinds of detection methods.

Imaging Systems

	GS-800™ Densitometer	ChemiDoc™ MP	Gel Doc™ EZ	PharosFX™ and PharosFX™ Plus
Type of Imager	Densitometer	CCD camera-based	CCD camera-based	Laser-based
Light source options	Epl- and transillumination of white light	Transillumination of UV and white light and Epi white, red, green and blue	Transillumination of UV and white light	488 nm external laser 532 nm internal laser 635 nm external laser
Optimized applications
Colorimetric stains	•	•	•	—
UV stains	—	•	•	—
Fluorescent stains and labels	—	•	—	•
Fluorescent multiplexing	—	•	—	•
Chemilluminescence	—	•	—	—
Stain-Free	—	•	•	—

Image Analysis Software

Computer-assisted image analysis is an indispensable tool for the evaluation of complex 2-D gels. Image analysis software obtains quantitative and qualitative information about the proteins in a sample and stores the information in files, which may also contain additional annotations. PDQuest™ 2-D analysis software is a tool for analysis of digitized gel images that integrates with Bio-Rad's image acquisition instruments.

Spot comparison with PDQuest software. PDQuest software can be used to compare two or more gel images, revealing changes in protein expression in response to different treatments, growth conditions or disease states.

The wizard driven software uses the following work flow:

PDQuest can also be used to control the ExQuest™ spot cutter for automated spot excision.

After separation by 1-D gel electrophoresis, you can utilize a number of methods for protein imaging and analysis involving staining techniques or stain-free technology in combination with specialized imaging devices and accompanying software.