American Society for Clinical Pathology (ASCP) Technologist in Cytogenetics certification (ASCP CG) Practice Test

In FISH, what is the purpose of using multiple fluorochromes?

1. To increase the resolution of the image

2. To enhance the detection of nucleic acids

3. To allow for color coding of different probes

4. To decrease background fluorescence

The correct answer is: To allow for color coding of different probes

Using multiple fluorochromes in fluorescence in situ hybridization (FISH) serves the purpose of allowing for color coding of different probes. This technique enables the simultaneous detection of multiple genetic targets on a single sample, facilitating the analysis of complex genomic rearrangements or the presence of multiple genes or chromosome regions. Each fluorochrome emits light at specific wavelengths, which can be distinguished from one another, allowing for clear visualization of different probes in a single experiment. This color coding is particularly beneficial in clinical cytogenetic applications, as it helps to identify specific chromosomal abnormalities and their relationships, providing a more comprehensive understanding of genetic alterations. The ability to visualize different genomic regions in distinct colors enhances the information obtained from a single sample and allows for more precise diagnoses.