Date of final editing: thursday, 26 june 2025
Brief analysis of genetic expression
Genetic expression analysis is the basis for understanding and regulating how genes work in different biological systems. Ish is a powerful technology that enables researchers to visualize the spatial and temporal expression of specific nucleic acid sequences either directly in tissue samples or in the entire tissue (the embryo). Scientists can use ish to test dna and rna sequences to gain insight into the active position and time of a given gene. The use of rna probes, especially reverse rna probes, has become the preferred method of in situ hybridism, thanks to their high sensitivity and specificity to the target rna sequence. The methodology is widely used in genetic expression research in areas such as developmental biology and disease pathology, where understanding of genetic activity is essential。
Phase 1 - sample storage
Proper storage of tissue samples is essential to preserve nucleic acid and ensure reliable in situ hybrid test results. In order to prevent degradation of the rna, tissue samples should be handled carefully and stored under conditions that inhibit rnase activity. Common methods include freezing samples in liquid nitrogen immediately after collection, or stationing them in ffl and then burying them in paraffins (i. E. Ffpe). Ffpe is particularly suitable for ish because they can be stored for long periods without significant loss of rna integrity. In any case, tissue samples should be kept in a cool and dry environment, avoiding repeated freezing cycles in order to maintain the quality of nucleic acids for downstream analysis。
Organizational preparation and slices
The preparation of tissue samples and slices is a necessary step in the in situ hybrid experiment programme. Proper fixation using reagents such as polymethaldehyde or ff would preserve the integrity of the structure and nucleic acid of the organization and make it easier to mix with probes. When the tissue is fixed, it is usually wrapped in paraffins in order to be sliced into thin slices with a thin slicer, resulting in tissue slices that can be sealed on the film for ish analysis. For certain applications, such as the study of genetic expression in zebra embryos, the use of whole embryo ish allows researchers to analyse the whole tissue or organism without slices. Carefully prepared tissues ensure that target nucleic acid sequences remain complete and can be used for special hybrids with rna or dna probes。
