Localization of elastase and tumor necrosis factor alpha mRNA by non-radioactive in situ hybridization in cultures of alveolar macrophages.

Digoxigenin is a new tool for labeling probes which can be detected with the help of specific antibodies in the cell by indirect or direct immunostaining. In contrast to the biotin-reaction, the advantage of digoxigenin is that it does not appear in animal or human cells in nature. In comparison to radioactive labeling methods it is favorable in terms of short exposure time and precise localization of signals in the cell. In this paper we describe the localization of elastase and tumor necrosis factor alpha (TNF alpha) mRNA by non-radioactive in situ hybridization of rat alveolar macrophages in cell culture after stimulation with welder steam dusts. Using digoxigenin labeled probes the determination of specific mRNA's expression and their precise localization in the cytoplasm of the cell could be achieved within one day.