This thesis is about the evaluation of a method to reuse May-Grünwald-Giemsa (MGG) or Papanicolaou (PAP) stained specimens of the lung for immunocytochemical detection of thyroidal transcription factor 1 (TTF1), cytokeratin 5/6 (CK5/6) and neural cell adhesion molecule (NCAM). These markers were chosen due to their role in specifying adeno-, squamous cell- and small-cell-lung-carcinoma. This is necessary especially for low differentiated, not clearly distinguishable forms of those carcinomas. By means of testing various combinations of work steps, work protocols were modeled to detect the three previously described markers. To test the efficiency of those protocols, 136 routinely stained, TTF1, CK5/6 or NCAM positive specimens were immunocytochemically stained. The quality of the staining process, assessed on a scale from 0 to 4, was compared to the original method (immunocytochemistry on native specimens). In addition, the marker-specific work protocols were compared to each other. The influence of the different types of routine-staining-methods, as well as the age of the specimens, on the staining result was also evaluated. A significant difference between the tested and the original method was found. There was also a significant difference between the three work protocols. The best results could be obtained while detecting CK5/6 on PAP-stained specimens. Although the age of the cell-material didn’t correlate negatively with the staining quality, fresh routinely stained (one week or less) specimens yielded significantly better results than those stored for a longer time period. If the staining protocols were further modified, the adaptation of the evaluated method for cyto-diagnostical routine operations in the Otto-Wagner-Spital is, due to its numerous advantages and the low additional expenditure of time, highly recommended.