Identification of inverted duplicated #15 chromosomes using bivariate flow cytometric analysis

Area of Science:

• Cytogenetics
• Molecular Biology
• Biotechnology

Background:

• Flow cytometry is a powerful tool for analyzing cellular components.
• DNA-specific dyes allow for the fluorescent labeling of chromosomes.
• Accurate identification of chromosomal abnormalities is crucial for genetic research.

Purpose of the Study:

• To develop a bivariate flow cytometry method for identifying abnormal human metaphase chromosomes.
• To validate the technique using chromosomes with known structural abnormalities (inverted duplicated #15).
• To assess the potential for separating abnormal chromosomes for genetic library construction.

Main Methods:

• Utilized a dual laser FACS IV cell sorter for bivariate flow histograms.
• Employed DNA-specific dyes 33258 Hoechst and chromomycin A3 for chromosome staining.
• Modified the flow cytometer with a specialized air-spaced achromat lens.
• Analyzed metaphase chromosomes from cell lines with inverted duplicated #15 autosomes.
• Performed counterstaining experiments with netropsin or distamycin A.

Main Results:

• Resolved approximately twenty distinct chromosomal fluorescence populations using the double staining technique.
• Successfully identified inverted duplicated #15 chromosomes in bivariate flow histograms from two cell lines.
• Observed a predicted relative increase in 33258 Hoechst fluorescence for abnormal #15 chromosomes after counterstaining.

Conclusions:

• Bivariate flow cytometry with specific DNA dyes can resolve and identify abnormal human chromosomes.
• The developed method allows for the identification of specific chromosomal abnormalities like inverted duplications.
• This technique holds promise for isolating abnormal chromosomes, facilitating DNA library construction for studying genetic disorders.