Dye-specific Antibodies

Visualize Molecular Weight Markers via Chemiluminescence or Fluorescence—in one step

SDS-PAGE is one of the most widely used techniques for protein analysis. It is frequently followed by Western blotting, which involves transfer of proteins to a membrane and their subsequent detection with antibodies coupled to an enzyme or fluorophore. In Western blotting, pre-stained proteins of known molecular weights are routinely used as markers to provide visual verification that the gel ran as expected, and to provide reference molecular weights to help identify proteins of interest. Unfortunately, these markers are not visible by chemiluminescence, the most commonly used Western blotting detection method that offers the advantage of signal amplification when protein abundance is low. Hence, the signals from proteins of interest and pre-stained marker proteins cannot be captured simultaneously by chemiluminescence or fluorescence detection methods. Researchers typically compensate by manually merging chemiluminescence results with the marker lane, potentially introducing error in calculating the molecular weight, which is fundamental to the identification of target proteins.

Anti-BLUE and anti-RAINBOW mouse monoclonal antibodies

Anti-BLUE (MABC1691) and anti-RAINBOW (MABC1690) mouse monoclonal antibodies bind the dyes used in molecular markers for Western blot, enabling simultaneous detection of target proteins and the molecular standard, by chemiluminescence or other detection methods.

To address this technical problem, we have introduced new antibodies specific for MW marker dyes. These unique monoclonal antibodies detect pre-stained molecular markers from different commercial sources without the need to perform manual marking of membranes and estimation of molecular weights.

  • Simultaneous visualization of markers and target protein
  • No cross-reactivity with target proteins
  • No background due to nonspecific binding
  • Compatible with any primary or secondary antibody in existing protocols
  • Exceptional sensitivity


MABC1690, purified antibody

MABC1690H, HRP-conjugated antibody

Anti-RAINBOW antibody detects all marker proteins in commercially available “Rainbow” markers, while lacking cross-reactivity with unstained proteins in whole cell lysates from a variety of species.

Anti-BLUE, clone 2D2-F11

MABC1691, purified antibody

MABC1691H, HRP conjugated antibody

Anti-Blue antibody, Clone 2D2-F11, is a unique monoclonal antibody that detects prestained Precision Plus Protein marker proteins and has been tested for use in Western blotting.  

PVDF membrane Pre-Stained Protein Standard (left image) and nitrocellulose membrane Pre-Stained Protein Standards (right image) were probed with MABC1691, Anti-BLUE, clone 2D2-F11 (0.5 µg/mL). Target bands were visualized using a goat anti-mouse IgG secondary antibody conjugated to HRP and a chemiluminescence detection system.

Pre-Stained Novex protein standard was probed with MABC1690, Anti-RAINBOW (1:250 dilution,left lane, and 1:500 dilution, right lane). Proteins were visualized using a goat anti-mouse IgG secondary antibody conjugated to HRP and a chemiluminescence detection system.

Table of MW-marker dye-specific antibodies available from MilliporeSigma

Product #  Description  Format
MABC1691 Anti-BLUE Antibody, clone 2D2-F11 purified
MABC1691H Anti-BLUE Antibody, clone 2D2-F11 HRP conjugated
MABC1691-25UG Anti-BLUE Antibody, clone 2D2-F11 purified, small pack
MABC1690 Anti-RAINBOW purified
MABC1690H Anti-RAINBOW Antibody, HRP conjugated
MABC1690-25UL Anti-RAINBOW purified, small pack