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

What is recommended to obtain more slides for analysis on a cultured CVS sample?

1. Trypsin-EDTA

2. Colony-stimulating factor

3. Amniotic fluid

4. Mitomycin C

The correct answer is: Trypsin-EDTA

Using trypsin-EDTA is a well-established method in cytogenetics for dissociating cells in culture, which makes it particularly suitable for obtaining more slides for analysis from cultured chorionic villus sampling (CVS) samples. Trypsin is a proteolytic enzyme that breaks down proteins, allowing cells to detach easily from the culture vessel, while EDTA acts as a chelating agent to bind calcium and magnesium ions that are essential for cell adhesion. This combination facilitates the separation of cultured cells without causing excessive damage, thereby preserving their viability and chromosome structure for effective analysis. In contrast, colony-stimulating factors are mainly involved in promoting the growth and differentiation of blood cells, which would not provide a direct benefit in increasing the number of slides from a CVS sample specifically. Amniotic fluid is a source of fetal cells but would not be directly used to enhance cultured CVS samples, and mitomycin C is a chemotherapeutic agent that inhibits cell division and is typically utilized in cytogenetic studies to prevent the overgrowth of normal cells. While it is important in some protocols, it does not serve the purpose of increasing slide availability from cultured CVS samples.