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

What is the likely outcome of inadequate Koehler illumination on chromosome imaging?

1. Lost resolution

2. Improved color representation

3. More accurate counts

4. Better contrast with brighter light

The correct answer is: Lost resolution

Inadequate Koehler illumination results in lost resolution when imaging chromosomes. Koehler illumination is critical in microscopy as it ensures even and optimal lighting across the specimen being observed. When this illumination is not properly set, it can cause uneven lighting, resulting in areas of the chromosome being either too dark or too bright. This lack of uniformity can obscure details and lead to degradation in image quality, making it difficult to accurately resolve fine structural elements of the chromosomes. In contrast, improved color representation, accurate counts, and better contrast with brighter light depend on proper illumination settings. Without adequate Koehler illumination, the clarity and detail necessary for accurate chromosome analysis are compromised. Therefore, the likely outcome of inadequate Koehler illumination is indeed lost resolution, impacting the overall accuracy of cytogenetic evaluations.