Qiagen lowered its full-year 2026 guidance after reporting preliminary Q1 net sales growth that missed expectations and remained pressured by external demand shifts. The company reported preliminary Q1 net sales of $492 million, up 2% year over year, while constant-currency sales fell 1% and came in below both its outlook and consensus. Qiagen cut its full-year CER net sales growth guidance from at least 5% to 1%–2%, and reduced adjusted diluted EPS at CER to a range from at least $2.43. The company pointed to headwinds including reduced Quantiferon-based immigration testing demand for latent tuberculosis and cautious life sciences spending in the US, along with elevated geopolitical uncertainty. Within the portfolio, sample technologies and its digital PCR business showed stronger momentum, while diagnostic solutions declined slightly, with Quantiferon down and QiaStat-Dx up modestly. For the diagnostics ecosystem, the update highlights sensitivity to government-linked and utilization-driven testing volume, even as instrument and consumables growth pockets persist.