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General product information for laboratory and clinic staff. It is not medical advice and does not interpret any individual result.
Short answer
HemoCue is a brand of point-of-care hemoglobin analyzers: a small photometer that reads a blood sample drawn into a disposable microcuvette. For the Hb 201+ model, the manufacturer describes a modified azide-methemoglobin reaction read at two wavelengths, 570 nm and 880 nm, with a result in 60 seconds from about 10 µL of whole blood. It is a different chemistry from the cyanmethemoglobin (HiCN) method that serves as the laboratory reference for hemoglobin.
Definition and scope
“HemoCue” is a manufacturer name, not a method. Searches for it sit next to older terms such as hemoglobinometer, Sahli, Tallquist and Drabkin, so this page separates them. A hemoglobinometer is the generic name for an instrument that measures hemoglobin. In the United States, the FDA lists hemoglobinometers (product code GIG) together with cyanomethemoglobin products (GKK and GJZ) under one regulation, 21 CFR 864.7500, “Whole blood hemoglobin assays”, as Class II devices. The regulation describes the category as reagents, calibrators, controls, or photometric or spectrophotometric instrumentation used to measure the hemoglobin content of whole blood for the detection of anemia, and it excludes automated hemoglobin systems.
Everything this page says about a specific analyzer comes from the manufacturer’s product sheet for the HemoCue Hb 201+. Other HemoCue models can differ, so check the sheet for the model you actually hold.
How it works in practice
The Hb 201+ sheet describes the measurement as follows:
- Chemistry: a modified azide-methemoglobin reaction.
- Optics: a dual-wavelength reading at 570 nm and 880 nm, used to compensate for turbidity in the sample.
- Sample: capillary, venous or arterial whole blood, about 10 µL, taken up by a microcuvette that is placed in the analyzer.
- Output: a result in 60 seconds across a measuring range of 0.5 to 25.6 g/dL (5 to 256 g/L, or 0.3 to 15.9 mmol/L). The analyzer stores 600 results and runs a built-in self-test.
- Calibration: the manufacturer states the analyzer is factory calibrated against the ICSH reference method and needs no recalibration. Control solutions are optional.
The maker positions the device for point-of-care use. For how such a testing station is organised, see equipping a point-of-care diagnostic station and point-of-care testing, and for the regulatory status of simple tests, the CLIA-waived test term and the CLIA-waived point-of-care testing guide.
Types and related methods: where HemoCue sits
The terms below are often searched together. This comparison places each by principle only, using the sources listed at the end of the page.
| Term | What it is | Basis |
|---|---|---|
| HemoCue Hb 201+ | Point-of-care analyzer with disposable microcuvettes | Modified azide-methemoglobin reaction, 570 nm and 880 nm (manufacturer sheet) |
| Cyanmethemoglobin / HiCN | Laboratory reference method for hemoglobin concentration | ICSH-recommended hemiglobincyanide method (van Assendelft et al., 1990) |
| Drabkin solution | Reagent named in cyanmethemoglobin-based assays | Described as the reagent in a 2018 Int J Lab Hematol study (PMID 29160616); FDA lists “cyanomethemoglobin reagent and standard solution” as product code GJZ |
| Hemoglobinometer | Generic name for a hemoglobin-measuring instrument | FDA product code GIG, 21 CFR 864.7500 |
Older visual-comparison terms such as Sahli, Tallquist and the hemoglobin color scale are separate from the photometric methods in this table. This page makes no performance claims about them.
Where it matters for labs, clinics and supply decisions
The sheet contains several details a lab or clinic would record when planning use of the Hb 201+ and its consumables:
- Microcuvette storage: an unopened vial is stored at 15 to 30 °C, and an opened vial is stable for three months.
- Operating temperature: 15 to 30 °C. The analyzer itself can be stored at 0 to 50 °C.
- Sample types accepted: capillary, venous or arterial whole blood.
- Quality control: a built-in self-test is included; control solutions are optional, so a site’s own quality policy decides whether to run them.
- Result capacity: 600 stored results.
The other side of the comparison is the reference method. A 1990 paper by van Assendelft, Horton and Parvin states that hemoglobin concentration for calibrating automated analysers should be determined by the ICSH-recommended HiCN method, and names the ways that method goes wrong: inadequate blood collection such as incorrect anticoagulation, inadequately calibrated pipettes, too little time for conversion to HiCN, turbidity of the measured solution, and transcription error. Read together, the two sources show a practical difference in who carries the calibration burden. With a HiCN procedure the lab controls collection, dilution, reaction time and reading. With the Hb 201+ the maker states that calibration is done at the factory against the ICSH reference. For general background on calibration, see what calibration is, and for a related photometric instrument, the microvolume spectrophotometer.
Common misunderstandings
- “HemoCue is the cyanmethemoglobin method.” It is not. The Hb 201+ uses a modified azide-methemoglobin reaction. It is calibrated against the ICSH reference method, which is the HiCN method, but it does not run that chemistry itself.
- “No recalibration” applies to every HemoCue. That statement comes from the Hb 201+ sheet. Do not assume it for another model without that model’s own sheet.
- “A hemoglobinometer is always a HemoCue.” Hemoglobinometer is the generic term, and the FDA code GIG covers the whole category.
- “A device on the market means a result can be read on its own.” The regulation describes these devices as used to measure hemoglobin for the detection of anemia. Interpreting a result for a person is a clinical decision for a qualified professional, and sits outside this page.
FAQ
What is a HemoCue?
A brand of point-of-care hemoglobin analyzers that read whole blood in a disposable microcuvette. The Hb 201+ gives a result in 60 seconds.
How does the Hb 201+ measure hemoglobin?
By a modified azide-methemoglobin reaction, measured at 570 nm and 880 nm, the second wavelength compensating for turbidity.
What is the cyanmethemoglobin method?
The hemiglobincyanide (HiCN) method recommended by ICSH as the reference for hemoglobin concentration. Drabkin’s solution is the reagent named in cyanmethemoglobin-based assays.
Is a hemoglobinometer the same as a HemoCue?
No. Hemoglobinometer is the general instrument category; HemoCue is one manufacturer’s product line.
Sources
- HemoCue, “Hb 201+” product sheet (GPM307FR), https://hemocue.com/wp-content/uploads/2026/03/Hb-201-GPM307FR-241107.pdf, checked 2026-10-30.
- U.S. Code of Federal Regulations, 21 CFR 864.7500, “Whole blood hemoglobin assays”, https://www.law.cornell.edu/cfr/text/21/864.7500, checked 2026-10-30.
- U.S. FDA, openFDA device classification database, product codes GIG, GKK and GJZ, https://api.fda.gov/device/classification.json, checked 2026-10-30.
- van Assendelft OW, Horton BR, Parvin RM. “Calibration and control in haemoglobinometry.” Clin Lab Haematol 1990;12 Suppl 1:31-42, PMID 2282764, https://pubmed.ncbi.nlm.nih.gov/2282764/, abstract checked 2026-10-30.
- Shah AP et al. “Evaluation of microtitre plate-based Haemoglobin estimation.” Int J Lab Hematol 2018;40(2):196-200, PMID 29160616, https://pubmed.ncbi.nlm.nih.gov/29160616/, abstract checked 2026-10-30.
