DGX vs ILMN Comparison

Quest Diagnostics is a leading independent provider of diagnostic testing, information, and services in the US. The company generates over 95% of its revenue through clinical testing, anatomic pathology, esoteric testing, and substance abuse testing with specimens collected at its national network of roughly 2,300 patient service centers, as well as multiple doctors offices and hospitals. The firm also runs a much smaller diagnostic solutions segment that provides clinical trials testing, risk-assessment services, and information technology solutions.

Illumina provides tools and services to analyze genetic material with life science and clinical lab applications. The company generates over 90% of its revenue from sequencing instruments, consumables, and services. Illumina's high-throughput technology enables whole genome sequencing in humans and other large organisms. Its lower throughput tools enable applications that require smaller data outputs, such as viral and cancer tumor screening. Illumina also sells microarrays (9% of 2024 sales) that enable lower-cost, focused genetic screening with primarily consumer and agricultural applications.