Enter your information to understand your hemoglobin levels.

The History of Hemoglobin

German physiologist Felix Hoppe-Seyler successfully crystallized and formally named hemoglobin in 1862, building on earlier work by researcher Friedrich Ludwig Hünefeld, who had first crystallized the reddish blood pigment back in 1840 without fully understanding its true biological function within the body. Hoppe-Seyler went considerably further, demonstrating conclusively that this crystalline pigment was directly responsible for binding and transporting oxygen throughout the bloodstream, a discovery that finally explained why blood carried oxygen so efficiently from the lungs to every distant tissue in the body. Nearly a century later, British molecular biologist Max Perutz spent over two decades painstakingly using X-ray crystallography to determine hemoglobin's precise three-dimensional molecular structure, an achievement so significant that it earned him the 1962 Nobel Prize in Chemistry and fundamentally launched the entire modern field of structural molecular biology as a distinct scientific discipline.

What Hemoglobin Actually Is

Hemoglobin is the iron-containing protein packed densely inside red blood cells, responsible for binding oxygen in the lungs and carrying it efficiently through the bloodstream to every tissue and organ throughout the entire body. Each hemoglobin molecule contains four separate protein subunits, and each of those subunits holds one iron-containing heme group capable of binding a single oxygen molecule, allowing one hemoglobin molecule to carry up to four oxygen molecules simultaneously at any given time. On the return journey, hemoglobin also helps carry carbon dioxide, the waste product of cellular metabolism, back to the lungs to be exhaled, making it genuinely essential to both halves of the continuous respiratory exchange process that keeps the entire body alive and functioning.

How Hemoglobin Is Measured

Hemoglobin has traditionally been measured using the cyanmethemoglobin method, a chemical reference technique in which a reagent converts all hemoglobin variants into a single, stable compound whose concentration can then be precisely determined using a spectrophotometer measuring light absorption. Modern automated hematology analyzers now measure hemoglobin electronically as part of a routine complete blood count, using photometric detection methods that deliver results within seconds rather than the many minutes the older manual chemical technique originally required of laboratory technicians. Point-of-care devices have also become increasingly common in recent years, allowing hemoglobin to be checked quickly and conveniently at the bedside or in a doctor's office using just a small finger-prick blood sample rather than a full venous draw.

Scientists Behind the Science

Felix Hoppe-Seyler's foundational nineteenth-century work gave the world its first genuine understanding of hemoglobin as a distinct, oxygen-carrying molecule, establishing the essential biochemical groundwork upon which the entire subsequent field of respiratory physiology would eventually be built. Max Perutz's decades-long structural investigation later revealed exactly how hemoglobin's four subunits work cooperatively together to bind and release oxygen so efficiently, a discovery that transformed scientists' understanding of protein structure and function far beyond hemoglobin alone. Together, spanning a full century of dedicated scientific effort, these two researchers turned a simple observation about blood's red color into one of the most thoroughly understood proteins in all of modern biochemistry and clinical medicine.