Labelling of an intermediate saccule of the Golgi apparatus and of parts of the endoplasmic reticulum by a lectin (soybean agglutinin) in the chick ciliary ganglion.

A lectin (soybean agglutinin or SBA) conjugated with horseradish peroxidase was used to identify the intracellular membranes containing galactose or alpha-N-acetylgalactosamine in young chick ciliary ganglions. The label is found on one or, less frequently, on two saccules of the Golgi apparatus in the ciliary and choroid neurones. The labelled intermediate saccules are always located either near the cisface or the middle region of the Golgi apparatus. This observation confirms that distinct compartments are present in the Golgi apparatus. Labelling is also frequently observed at the end of the rough endoplasmic reticulum cisternae in the neurones. It is also sometimes observed in a few vesicles. The lectin-peroxidase labelling, however, was never observed in Schwann cell Golgi apparatus or in their rough endoplasmic reticulum.