SIDEBAR: The Rise of Multi Channel Analyzers in Clinical Chemistry

 SIDEBAR to a broader article.

Sidebar to the Sidebar: When Did Multi-Channel Analyzers Become Common—and Why Do We Still See the Same Panels Today?

Multi-channel automated analyzers began to enter routine clinical laboratory use in the late 1970s and early 1980s, but they became truly widespread during the mid-to-late 1980s and early 1990s. This was the period when hospital and reference laboratories transitioned from largely manual or single-analyte chemistry testing to high-throughput platforms capable of measuring many analytes simultaneously from a single specimen. By the time OIG issued its guidance in 1997 and 1998, these analyzers were no longer experimental curiosities—they were the backbone of routine clinical chemistry.

The key innovation was not simply speed, but parallelization. Earlier analyzers performed one test at a time. Multi-channel analyzers, by contrast, were designed to run multiple assays together because it was operationally easier, cheaper, and analytically cleaner to do so. Once serum was loaded and the instrument calibrated, adding additional analytes often required little incremental effort. This technological reality collided directly with a reimbursement system that still conceptualized testing as a series of individually ordered services.

Out of this collision emerged the chemistry panels that are now so familiar they barely register as “panels” at all. The Basic Metabolic Panel (BMP)—typically including sodium, potassium, chloride, bicarbonate, BUN, creatinine, glucose, and sometimes calcium—reflects a core set of electrolytes and renal markers that were commonly run together on early automated systems. The Comprehensive Metabolic Panel (CMP) expanded this set to include liver-associated analytes such as AST, ALT, alkaline phosphatase, bilirubin, albumin, and total protein, yielding the familiar 14-analyte version used today. Variants with 20 or 21 analytes emerged historically as laboratories added calcium, phosphorus, or other markers depending on platform design and clinical convention.

What is often forgotten is that these panels were not originally “bundles” in a conceptual sense. They were engineering artifacts—groupings that made sense given how the machines worked. Physicians quickly adapted their ordering habits to these groupings because they were clinically useful and readily available. Over time, CPT coding and Medicare policy caught up, formalizing what had started as a technological convenience into standardized billable panels.

By the mid-1990s, however, policymakers faced a new question: what happens when technology makes it easier to run more tests than are clinically necessary for a given patient? OIG’s answer, reflected in the 1997 and 1998 guidance, was not to resist the technology, but to regulate the billing behavior around it. Laboratories could run broad panels if that was how their analyzers worked—but they could not bill indiscriminately.

Seen in this light, modern molecular panels are not a radical departure from historical practice. They are the genomic descendants of the chemistry analyzer. Just as it once made sense to run electrolytes and liver enzymes together, it may now make sense to sequence genes A, B, and C together. The regulatory question has remained strikingly stable for forty years: what matters is not what the machine runs, but what the laboratory reports and bills as medically necessary for each patient.

That continuity is precisely why the 1997–1998 OIG guidance still resonates today.