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

What is the primary purpose of using Trypsin-EDTA in cell culture?

1. To fix cells for staining

2. To encourage cell growth

3. To detach cells from a culture surface

4. To enhance DNA replication

The correct answer is: To detach cells from a culture surface

The primary purpose of using Trypsin-EDTA in cell culture is to detach cells from a culture surface. Trypsin is a proteolytic enzyme that breaks down proteins, facilitating the dissociation of adherent cells from the substrate they are cultured on. When cells need to be passaged or analyzed, Trypsin-EDTA is applied, allowing for the separation of the cells without causing damage to their structure or function. In this context, the use of EDTA serves to chelate calcium ions, which helps to disrupt cell adhesion more effectively. This combination is essential in maintaining the viability of the cells during the detachment process. By employing Trypsin-EDTA, researchers can ensure that the cells remain healthy and suitable for further experimentation or culture conditions. The other choices involve processes that are not associated with the specific function of Trypsin-EDTA. For instance, using it for cell fixation or staining contradicts its role, as fixation typically involves a different set of chemicals that preserve cell morphology rather than detaching cells. Encouraging cell growth is related to the culture medium and conditions rather than the detachment process, while enhancing DNA replication pertains to cellular processes that are independent of the detachment method employed.