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

Which type of microscope is typically used when cleaning a chorionic villus sample?

1. Fluorescent microscope

2. Phase contrast microscope

3. Dissection microscope

4. Transmission electron microscope

The correct answer is: Dissection microscope

The dissection microscope, also known as a stereo microscope, is the most appropriate choice for cleaning a chorionic villus sample because it provides a three-dimensional view of the specimen at low magnification, allowing for easier manipulation and observation of delicate structures. This type of microscope is designed for visualizing larger specimens, making it ideal for examining the chorionic villus tissue without the increased complexity and risk of damage associated with higher magnifications. While other microscopes serve critical roles in laboratory settings, they are not suited for this specific task. For instance, a fluorescent microscope is used to identify specific molecules or structures within cells through the use of fluorescent dyes, but its high levels of magnification and specialized lighting are unnecessary for simply cleaning a sample. The phase contrast microscope enhances the contrast of transparent specimens, allowing for better visualization of living cells, but again, its capabilities are beyond what is needed for cleaning a chorionic villus sample. Lastly, a transmission electron microscope provides extremely high-resolution images of thin sections of samples, but it is not designed for the examination of larger and bulkier structures like chorionic villi, making it impractical for this purpose.