Which banding technique is used to stain chromosomes to reveal AT-rich regions?

The correct answer is QFQ staining, which is a technique used to stain chromosomes specifically highlighting AT-rich regions. QFQ stands for Quinoxaline Fluorescence Quenching and is a method that employs fluorescent dyes that preferentially bind to regions of the genome that are rich in adenine (A) and thymine (T). This property allows the visualization of chromosomal features that might be less discernible with other staining methods.

Differentiating characteristics of QFQ staining make it particularly useful in cytogenetic studies where identification of chromosomal abnormalities in AT-rich areas is necessary. This is essential for diagnosing specific genetic disorders and understanding chromosomal structure in greater detail.

In contrast, G-banding typically reveals patterns based on the presence of GC-rich sequences, and R-banding does the opposite by staining GC-rich regions, making it less useful for the specific identification of AT-rich areas. C-banding focuses on the centromeric regions of chromosomes and is used primarily for distinguishing different chromosomes and understanding chromosomal architecture, rather than revealing AT-rich areas.