Histotechnology I- Miscellaneous
Question No. 16. The Answer is: (D) The probe must be DNA in nature.
Discussion: In situ hybridization can be used to detect the presence or absence of a specific sequence of DNA or RNA in tissue sections, cytologic preparations, and sometimes whole mounts of tissue. It is sequence specific. The process involves annealing of the probe polynucleotide with the target sequence. Probe sequences longer then 500 base pair will have steric hindrance and will be difficult to hybridize. The probe, however, can be made of both DNA or RNA (riboprobe). Signal can be visualized with enzyme-linked or fluorescent methods. Radioactive signal can also be visualized by photographic emulsions (autoradiography).