Policies

Immunogold Labeling

TEM with immunolabeling

We offer three general approaches for immunolabeling:

Pre-embedding immunolabeling  protocol similar to immunofluorescence but substituting a colloidal gold tagged secondary antibody

Post-embedding immunolabeling  fixation in paraformaldehyde/glutaraldehye mixture followed by gentle dehydration, embedding in water miscible acrylic resin (LR Gold), and labeling of ultrathin sections

Cryoimmunolabeling  fixation in paraformaldehyde/glutaraldehyde, sucrose cryoprotection, followed by rapid freezing and labeling of ultrathin cryosections (Tokoyasu method)

It is not possible to predict in advance which will be the most successful method; every antigen is different. High-quality structure preservation and preservation of antigens are often mutually incompatible. Multiple attempts might be needed to optimize the protocol. To recover our costs, we charge by the hour.

To maximize the chances of a favorable outcome, we will not accept an immunolabeling project that does not meet one or both of the following criteria:

  • Convincing published data showing successful immunogold labeling with the same brand and catalog number of primary antibody.
  • Successful immunofluorescence labeling of your sample using our immunoEM fixation and permeablization protocol. We supply suitable fixatives for testing.