Types of Gel & Blot Imagers

Following electrophoresis or immunodetection, gels and blots can be imaged and analyzed using a variety of imaging systems. The signals are digitized by dedicated image acquisition devices, data is analyzed with sophisticated software and then stored for later use.This section provides an overview of the suite of gel and blot imaging systems that Bio-Rad offers, highlights their features, and discusses their respective applications.

Imaging and analysis systems


Related Topics: Image Analysis Software.

Page Contents

Densitometers are based on high-performance document scanners utilizing visible light for analysis of electrophoresis gels and blots stained with visible dyes. Bio-Rad's GS-900™ Calibrated Densitometer can be used to image both gels and blots and has a linear response up to 3.0 optical units in gray levels.

GS-800 calibrated densitometer

GS-900 Calibrated Densitometer

Charge-Coupled Device (CCD) Cameras

Charge-coupled device (CCD) cameras operate with either transillumination, provided by UV or visible light boxes positioned underneath the gel or blot for imaging a variety of stains (Coomassie, silver, fluorescence), or epi-illumination, which detects blots using colorimetric or fluorescent techniques. Supercooled CCD cameras reduce image noise, allowing detection of faint luminescent signals.

The ability to visualize gels without a staining step has gained popularity recently. Stain-free technology has several advantages over staining procedures. In particular, it eliminates the need for a lengthy destaining step, makes visualization faster and more efficient, and eliminates disposal of organic waste generated during destaining. The stain-free enabled imagers come with an automated imaging and analysis system and give less background compared to traditional Coomassie staining procedures, thereby reducing variability between and within gels.

See how you can streamline your protein electrophoresis and western blotting experiments.

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Stain-Free Technology
ChemiDoc Touch system ChemiDoc MP system Gel Doc XR+ system Gel Doc XR+ system Gel Doc EZ system
Stain-Free Enabled
ChemiDoc MP
Stain-Free Enabled
Stain-Free Enabled
ChemiDoc XRS+
Stain-Free Enabled
Gel Doc XR+
Stain-Free Enabled
Gel Doc EZ System


  • The ChemiDoc MP System is a full-featured imaging system that offers the best RGB/NIR fluorescence and chemiluminescence western blot detection and image quality, features that are easy to learn with Image Lab Touch Software.
  • The ChemiDoc Imaging System provides chemiluminescence sensitivity that matches x-ray film with the optional upgrade to fluorescence detection (ChemiDoc MP Imager).
  • The ChemiDoc™ XRS+ System is the fastest completely automated detection system for chemiluminescence, fluorescence, and colorimetric imaging controlled by Image Lab Image Capture and Analysis Software
  • The Gel Doc™ XR+ System is a fast, easy-to-use, completely automated gel imaging and documentation system controlled by Image Lab Image Capture and Analysis Software
  • The Gel Doc™ EZ System is a compact and automated imaging system. Trays specific for different applications afford flexibility and the Image Lab™ Software provides publication-quality images and analyzed results with the push of a button

See the Imaging Systems Selection Guide below for full details of the capabilities of each imaging system.

Bio-Rad Gel and Blot Imaging Systems Selection Guide

  ChemiDoc Touch ChemiDoc Touch Gel Doc XR+ GelDoc EZ GS-900
ChemiDoc™ ChemiDoc™
Gel Doc™
Gel Doc™
Nucleic Acid Detection
Ethidium Bromide
SYBR® Green I and SYBR® Safe Dyes
Fast Blast™ DNA Stain
Protein Staining, 1-D Gels
Stain-Free Gels
Coomassie Blue Stain
Silver Stain
SYPRO Ruby, Flamingo™, and Oriole™ Gel Stains
Protein Staining, 2-D Gels
Coomassie Blue Stain
Silver Stain
SYPRO Ruby, Flamingo™, and Oriole™ Gel Stains
Cy2, Cy, Cy5 Label
Blot Detection
Multiplex Fluorescence
Stain-Free Blots
Colorimetric Blots
SYPRO Ruby Protein Blot Stain*

*  Optimal with low fluorescence PVDF membrane.


Gel Doc EZ System Tour
In this interactive demonstration, you will be able to test drive the Gel Doc EZ imager and dig deeper into the instrument's capabilities, specifications, and features.


Number Description Options
ChemiDoc Touch Imaging System Brochure, Ver D