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

What type of culture is adopted to obtain chromosome preparations from amniotic fluid?

1. Long-term culture

2. Short-term culture

3. Suspension culture

4. Confluent culture

The correct answer is: Short-term culture

The appropriate method for obtaining chromosome preparations from amniotic fluid is short-term culture. This technique is commonly employed because the cells from amniotic fluid, particularly the fetal cells, can be cultured quickly in a controlled environment. Short-term cultures allow for rapid expansion and harvesting of the cells, typically within 48 to 72 hours. This timeframe is crucial when analyzing chromosomes, particularly for prenatal genetic diagnosis. In this context, short-term culture is particularly effective as it preserves the mitotic characteristics needed for high-quality cytogenetic analysis. This includes the ability to obtain metaphase chromosomes, which are necessary for karyotyping and other cytogenetic evaluations. Long-term culture, on the other hand, generally refers to cultures that extend beyond a few days, which may not be suitable for amniotic fluid cells that require fast turnaround times for diagnostic purposes. Suspension culture primarily encompasses the growth of cells in a liquid medium without attachment, which is less relevant for preparing structured chromosome preparations from adherent or semi-adherent cell types. Confluent culture typically refers to a state where cells cover the entire surface of the culture vessel, which is a stage generally reached after prolonged culture and not applicable for quickly analyzing fetal cells from amniotic fluid. Thus,