When harvesting peripheral blood cultures, aseptic technique is less critical following the use of?

The correct choice highlights the use of Colcemid in the context of harvesting peripheral blood cultures. Colcemid is a mitotic inhibitor that disrupts the spindle formation during cell division, specifically at metaphase. Its primary role in cytogenetics is to synchronize the cells and enable the accumulation of metaphase cells, which enhances the visualization of chromosomes during analysis.

In the context of harvesting peripheral blood cultures, aseptic technique is important to prevent contamination that could interfere with the results. However, when Colcemid is applied, the cells are arrested in metaphase, which can somewhat mitigate the impact of contamination in subsequent analysis because the chromosomes are isolated and the focus shifts to those actively dividing.

Additionally, Colcemid is typically used in controlled laboratory conditions where other aseptic measures are employed during the culture preparation. While aseptic technique is still a best practice, the use of Colcemid can make it less critical in terms of the impact on the immediate cytogenetic analysis, provided that standard sterile techniques are maintained.

The other substances listed, such as Hematoxylin, Formalin, and Ethanol, serve distinct roles: Hematoxylin is a dye used for staining, Formalin is a fixative that preserves tissue