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

Which type of culture allows for easier distinction between mosaicism and pseudomosaicism and has a decreased turnaround time?

1. Cultured lymphocytes

2. In situ-amniotic fluid culture

3. Direct blood smear culture

4. Bone marrow culture

The correct answer is: In situ-amniotic fluid culture

The type of culture that allows for easier distinction between mosaicism and pseudomosaicism while also providing a decreased turnaround time is in situ-amniotic fluid culture. This technique involves culturing cells directly from amniotic fluid, which contains fetal cells. The primary advantage is that it allows for the analysis of cells in their natural state, which can help differentiate between true mosaicism (where different cell lines exist within the individual) and pseudomosaicism (which may arise from culture artifacts or other factors). In situ culture offers a rapid turnaround time compared to traditional cultured lymphocyte methods, as it can provide results from fetal cells without the need for extensive manipulation. This is particularly crucial in prenatal diagnosis when time-sensitive decisions may be necessary. In contrast, cultured lymphocytes, while valuable for many cytogenetic analyses, may not distinguish between mosaicism and pseudomosaicism as clearly and take longer due to the steps involved in culturing peripheral blood lymphocytes from the sample. Direct blood smear cultures, while easy and fast, may lack the resolution needed for cytogenetic analysis and thus would not provide sufficient clarity on mosaicism versus pseudomosaicism. Bone marrow cultures are critical for hematological evaluations but can also result in prolonged turnaround times and