Summary—Cryomethods occupy a privileged position among the procedures used for the preparation of biological samples for the various studies that may be performed in electron microscopy (ultrastructural, immunocytochemical and microanalysisin situ). In general, cryomethods are specific to one, or a maximum of 2 types of application. The (3‐Cryo) methods (cryofixation, cryosubstitution without fixatives and cryoembedding in the new Lowicryl resins (K11M or HM23) are a set of methods for correlating new structural information with analytical and biochemical data. However, these 3‐Cryomethods are delicate, complicated and expensive. To demonstrate that they can be performed, at least in part, with home‐made systems at a reasonable cost, we have carried out a structural and immunocytochemical study on the oviduct of the laying quail. We studied the localization of 2 proteins, one cytoplasmic (ovalbumin) and the other nucleolar (B‐36). The results provided by the 3‐Cryomethods are compared with those obtained with other immunocytochemical methods, including tissue processed by conventional chemical fixation and high or low temperature embedding, or by 2‐Cryomethods (cryofixation and cryo