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

Which factor is most important when preparing stained chromosomes for digital imaging?

1. Contrast of the stain

2. Uniformity of chromosome size

3. Fixation time

4. Cellular adhesion

The correct answer is: Contrast of the stain

The most important factor when preparing stained chromosomes for digital imaging is the contrast of the stain. High contrast in the staining process enhances the visibility of chromosomal features, making it easier to differentiate between individual chromosomes and their respective structures. Adequate contrast allows for clearer imaging, which is critical for accurate analysis and interpretation of chromosomal abnormalities. When preparing samples for digital imaging, the clarity and distinction of chromosomal banding patterns are vital to detect subtle differences and abnormalities that could indicate genetic disorders. Stains that provide high contrast help in highlighting these features, which is essential in cytogenetic evaluations. While other factors, such as uniformity of chromosome size, fixation time, and cellular adhesion, do play roles in the overall quality of cytogenetic preparations, they do not directly impact the visual clarity and the detail visibility needed for effective digital imaging as much as the contrast of the stain does. This makes contrast a priority in ensuring high-quality images that are essential for accurate diagnostic assessments.