dGH SCREEN

What is dGH SCREEN?

SCREEN: Single-Cell Rearrangement Event Evaluation and Numbering

dGH SCREEN™ is a single cell assay designed to monitor structural variants throughout the genome in an entirely de novo fashion. By utilizing directional Genomic Hybridization technology combined with fluorescence labeling patterns and chromosomal aggregation strategies, dGH SCREEN provides the most comprehensive and high-resolution karyographic analysis available.

Figure 1: Example of the first step in the dGH SCREEN analysis process. A metaphase spread is hybridized with 5 color dGH probes designed to measure known and unknown variants in order to provide a whole genome survey of structural rearrangements in a single cell.

With dGH SCREEN, researchers are able to track and localize a wide variety of chromosomal rearrangements within a 10kb limit of detection:

  • Exchange Events including reciprocal, balanced and allelic translocations
  • Orientation Events including inversions, recombinations and sister chromatid exchanges
  • Chromosomal Gain & Loss Events including sister chromatid fusions, dicentrics/acentrics, fragmentation/chromothrypsis, polypoidy, aneuploidy, monosomy, polysomy
SCREEN: Sort

Figure 2: Step 2 in dGH SCREEN analysis. Chromosomes are sorted by color and morphology to enable localization of rearrangement events.

dGH SCREEN Applications: 

  • Monitoring Cellular Engineering Outcomes: Genome-wide, cell-by-cell and chromosome-by-chromosome assessment of structure, pre- and post modification
  • Orthogonal Data for Sequencing: Genome-wide, confirmatory data regarding rearrangements predicted with long read and other NGS analyses
  • Structural Integrity QC: A straightforward yardstick by which to measure the relative stability of cell lines, or to screen and compare candidate cell lines, based on total genomic structural variation metrics.
  • Variant Discovery: Discover previously unknown mutations by de novo assessment of single cells from patient sub-types
  • Genomic Stability Assessment: Track persistence of variants over time, passages, process variable changes, etc.
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SCREEN: Karyograph
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Chromosome 1 with small inversions visible in both p and q arms

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Example of monosomy in chromosome 4

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Large sister chromatid exchange event present in the q arm of chromosome 6

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Monosomy of chromosome 15

Example Data Output

Figure 3: Step 3 in dGH SCREEN analysis. Chromosomes are organized karyographically and aggregate sample rearrangement data is gathered for analysis of genomic stability and structural integrity.

In addition to being an unbiased tool for the detection of structural variants throughout the genome,  dGH SCREEN offers high resolution analysis of DNA repair activity by monitoring hallmarks of genomic instability, including sister chromatid exchanges.

This analysis produces vast amounts of rearrangement data which can be used to create stability and structural variance profiles for complex and heterogeneous cell populations, making dGH SCREEN one of the most comprehensive and robust karyographic assays available.

For more information on how dGH SCREEN can inform your research, you can contact probes@kromatid.com and we will reach out to you shortly!