Peace broke out last week between gene sequencing rivals Illumina Inc. and Qiagen N.V. But before lawyers could pack up their files, a new patent war was taking shape.

On Friday, Illumina, Columbia University and its licensee Qiagen settled their 5-year-old patent litigation. Qiagen agreed to stop using with its GeneReader machine a method for labeling nucleic acid molecules that was patented by Illumina.