Summary
A bioRxiv preprint describes RaMN-Seq, a roughly two-hour method for purifying micronuclei and sequencing their DNA. The researchers report tests in induced chromosome-missegregation experiments and cancer cell lines and tumour samples.
A research team reports RaMN-Seq, a kit-style workflow that purifies micronuclei in about two hours and sequences DNA from individual micronuclei using low-pass sequencing. In a bioRxiv preprint posted on 16 October 2026, the researchers say the method recovers a known chromosome bias in an induced missegregation experiment and can be used with cancer cell lines and fresh-frozen tumour samples.
Why sequence micronuclei?
Micronuclei are small structures outside a cell’s main nucleus. They can form when chromosomes are incorrectly separated during cell division, leaving chromosome material in a separate compartment. Their contents can therefore offer clues about which chromosomes were affected by genomic instability.
The membranes around micronuclei can rupture. Such structures have been proposed as an intermediate in chromothripsis, a form of extensive chromosome rearrangement associated with cancer. The preprint examines whether the chromosome contents of ruptured micronuclei differ from those that remain intact.
What RaMN-Seq found
The workflow combines micronucleus purification with sequencing of each isolated structure. The authors describe the purification as taking about two hours and present RaMN-Seq as a simpler, less expensive alternative to single-cell genome sequencing for examining the chromosome identities of material affected by instability.
In diploid cells treated with nocodazole washout to induce chromosome missegregation, RaMN-Seq recovered the previously known bias in which chromosomes were missegregated. The researchers also compared ruptured, cGAS-positive micronuclei with intact ones. They report no substantial differences between the groups in chromosome content or micronucleus size.
The team applied the method to cancer cell lines and fresh-frozen tumour samples, reporting that it can be used to explore chromosome instability in these sources. The abstract does not specify the chromosome patterns found in those cancer samples, so the principal detailed result described there is the induced-missegregation experiment and the comparison of rupture states.
By analysing micronuclei individually, the method offers a way to study chromosome material separated from the main nucleus, rather than only the genome of the whole cell. The findings are preliminary: this is a bioRxiv preprint, and the abstract does not provide sample sizes or detailed performance measures for assessing the breadth of the validation.