Immunogold labelling

Immunogold-labelling with colloidal gold is a technique used for the localisation of antigenic sites at the ultrastructural level.

In the Tokuyasu-method for cryo-sectioning (Tokuyasu, 1973) we use sucrose-embedded biological samples which have been plunge-frozen in liquid nitrogen to create amorphous, vitreous, ice. We can obtain ultrathin sections of that frozen material using the RMC LN Ultra microtome. Thawed cryo-sections will then be labelled using a primary antibody of choice and the antibody localisation can then be visualised in a secondary step using a gold colloid which binds to the primary antibody. The electron-dense gold particles can be easily identified in the transmission electron microscope and enable the quantitation of the gold label in relation to the compartments of interest.

Alternatively, biological specimen can be embedded in a resin that allows for the preservation of the antigenicity, e.g. Lowicryl resins or LR White.

References:

Tokuyasu, K.T. (1973) A technique for ultracryotomy of cell suspensions and tissues. J Cell Biol 57: 551–565.

Immunogold labelling of GFP signal inside peroxisomes of Ustilago maydis

Immunogold labelling of GFP signal inside peroxisomes of Ustilago maydis