The ability to determine spatial and temporal microRNA (miRNA) accumulation at the tissue, cell and subcellular levels is essential for understanding the biological roles of miRNAs and miRNA-associated gene regulatory networks. This protocol describes a method for fast and effective detection of miRNAs in frozen tissue sections using fluorescence in situ hybridization (FISH). The method combines the unique miRNA recognition properties of locked nucleic acid (LNA)-modified oligonucleotide probes with FISH using the tyramide signal amplification (TSA) technology. Although both approaches have previously been shown to increase detection sensitivity in FISH, combining these techniques into one protocol significantly decreases the time needed for miRNA detection in cryosections, while simultaneously retaining high detection sensitivity. Starting with fixation of the tissue sections, this miRNA FISH protocol can be completed within approximately 6 h and allows miRNA detection in a wide variety of animal tissue cryosections as well as in human tumor biopsies at high cellular resolution.

Objectives

In this study, normal prenatal standards were established for the early development of the vertebral column. These standards can be used in the future--for evaluation of pathologic deviations in the human vertebral column in the second trimester.

In normal fetuses, the base or footplate of the vomeral bone appears from 16 weeks MA in frontal sections. In fetuses with isolated cleft palates, with no connection between the nasal septum and the maxillary processes, this vomeral footplate does not develop in the period observed (14 to 19 weeks MA).