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

What is a common observation under an electron microscope as a result of all banding procedures?

1. Chromosomal duplication

2. Chromosomal collapse

3. Increased chromatin density

4. Chromosomal fragmentation

The correct answer is: Chromosomal collapse

The correct observation under an electron microscope as a result of all banding procedures is chromosomal collapse. This phenomenon occurs during the process of preparing chromosomes for banding analysis, where the chromosomes are typically subjected to treatments that can lead to structural changes, including the collapsing of chromosomal material to reveal distinct banding patterns. Banding techniques, such as G-banding, Q-banding, or C-banding, preprocess chromosomes in ways that allow for better visualization of their structure by compacting the chromatin. The collapse of chromosomes helps in making it easier to interpret the banding pattern, which is essential for identifying chromosomal abnormalities. The other options refer to different structural changes or conditions that do not directly result from banding techniques. Chromosomal duplication would suggest the presence of an extra copy of a chromosome, which is unrelated to the preparation methods used to enhance banding. Increased chromatin density might occur due to the compaction process, but it is not specifically observed as a result of banding procedures in the same way chromosomal collapse is. Chromosomal fragmentation may imply breaks in chromosomes, a different issue not directly correlated with the standard techniques utilized for banding. In summary, chromosomal collapse accurately depicts the changes observed under an electron