KromaTiD, a Colorado State University spin-off company, recently announced the development of the first fluorescent “paint” designed to color chromatids – or one side of the chromosome. The paint, a mixture of fluorescent DNA molecules tailored to a particular chromosome, allows scientists to see rearrangements that occur within individual chromosomes and will greatly improve detection of chromosomal rearrangements, particularly difficult-to-detect inversions.

An inversion is a broken piece of DNA that flips around before rejoining back into the chromosome. Using KromaTiD’s technology, a chromosome inversion will appear as a fluorescent spot that switches from one side – or one chromatid – to the other, providing an easily identifiable visual picture of the rearrangement.

“The paint assigns itself to one side of the chromosome depending on its design, and then jumps from that side to the other if there is an inversion present,” said Dr. Andrew Ray, an Associate Professor in the Department of Environmental and Radiological Health Sciences, and co-founder of KromaTiD.

Chromosomal inversions are associated with genetic abnormalities – such as neurological and developmental disorders including autism – and many diseases including cancer. Inversions also occur when someone is exposed to ionizing radiation, a known cause of cancer. KromaTiD’s paint improves detection of inversions by at least tenfold over current approaches and dramatically increases detection certainty. Chromatid paints also can be used to assess the risk of exposure in any one individual, such as an astronaut exposed to radiation in space.

Dr. Susan Bailey with student

“Chromatid paints will provide scientists with an easy-to-read test,” said Dr. Susan Bailey, an Associate Professor in the Department of Environmental and Radiological Health Sciences and co-founder of KromaTiD. “Until now, detecting these inversions has been extremely difficult if not impossible. Once we know where the problem inversions are, we can discover new disease and cancer-related genes and go after them for diagnosis and treatment."

KromaTiD currently has chromatid paint for human chromosome number 3, a chromosome made up of 200 million base pairs. The chromatid paint “kit” for that chromosome uses about 200,000 tubes of unique DNA that highlight 200 individual spots along the chromosome. The company is working to develop 22 more paint kits, one for each human chromosome, plus the X and Y. The technology also can be developed for other species including dogs and horses.

KromaTiD is a startup company based on licensed technology from CSU and the University of Texas Medical Branch in Galveston. The company is funded primarily through a Small Business Innovation Research Award from NASA. Additional support has come from CSU College Research Council, CSU Research Foundation, CSU Ventures, CSU Cancer Supercluster, Colorado’s Office of Economic Development Bioscience Evaluation Grant Program and the National Institutes of Health.