Teaching collections are of great importance for science instruction at any level. There are several problems linked to the handling and curatorial management of this kind of collection. Among these is the relatively short life-span of specimens, due to the damage from continuous handling by students. Often the specimens used to replenish the teaching collection come from sampling in field. This is at odds with the ethics of conservation and the use of and experimentation on animals in biology. The technique proposed in the present work is an effective and low-cost way to build a macroinvertebrate wet teaching collection and store invertebrate animals for pedagogical purposes, preserving the specimens, and allowing the use of rare or fragile specimens in school and university teaching settings as well as in training courses programmes. A collection preserved in alcoholic gel has been used to test a handbook for identification of aquatic macroinvertebrates from Rio de Janeiro State, Brazil, and in theoretical-practical lessons for training students in the water quality research programme in the Oswaldo Cruz Foundation/Ministry of Health, Brazil. (Contains 6 figures.)