What technique can be used to prevent overspreading of chromosomes when using a new hypotonic solution?

When preparing chromosome spreads for karyotyping, it's crucial to manage the drying process effectively to preserve the structural integrity of the chromosomes. Using a new hypotonic solution can lead to overspreading of chromosomes if the spreading is not controlled properly. Reducing the drying time can be beneficial in this context. A shorter drying time can help maintain the chromosomes in a more compact arrangement, which minimizes their tendency to spread out excessively.

This careful control of drying allows the chromosomes to remain adequately hydrated and prevents them from drying up too quickly, which can lead to tails forming and potentially overlapping or becoming too widely spaced apart. Finding the right balance in drying time is essential, and in this case, reducing that time provides the right solution to prevent overspreading.