NTU Undergraduates' research April 2014 - Biosciences | Page 15

The detection of microRNAs in the hippocampus of the rodent brain.
David Gibbons, N0360578.
Nottingham Trent University.
Abstract

In-situ hybridisation is a technique commonly used to detect and locate genetic sequences within
cells and tissues. A complementary probe to this genetic sequence would be developed and labelled,
to allow detection once the in-situ hybridisation reaction has taken place; depending on the label
used i.e. radiolabel or a fluorescent label, will affect the interpretation of the results, a radiolabel
(35S) was chosen to label the probe developed for this experiment. The in-situ hybridisation
technique was adjusted to allow the detected of microRNAs within the tissue samples, as they are
much smaller than the molecules usually identified using this technique. microRNAs are small nocoding RNA molecules approximately 22 nucleotides in length, which play a crucial role in the
silencing of genes, via binding to the 3’ untranslated region of mature RNA molecules. A rodent brain
was sectioned and fixed onto microscope slides ready for the radiolabelled oligonucleotide probe to
be introduced, and the in-situ hybridisation reaction to occur. Once completed, the slides were
collected and exposed to an autoradiograph to capture any emitted radiation from any bound
probe, and then the film was developed to allow the visualisation of any results. Looking at all the
brain tissue sections exposed to the probe, no signal was detected on any tissue section. Therefore is
the in-situ hybridisation experimental process reliable and specific enough to allow the binding to
and visualisation of microRNA molecules within cells and tissues.