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Updated: Aug 10, 2026
A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering
Published on: December 7, 2016
Hemoglobin C and hemoglobin O-Arab variants can be diagnosed using the Bio-Rad Variant II high-performance liquid
Alla Joutovsky1, Michael Nardi
1Department of Pathology, New York University School of Medicine and Bellevue Hospital Center, New York, NY 10016, USA.
Context:
Current standards for laboratory accreditation from the College of American Pathologists state that when high-performance liquid chromatography (HPLC) is used as a screening test, all non-A, non-S abnormal hemoglobin (Hb) variants must be confirmed by an alternative method, including alkaline and acid electrophoresis.
Objective:
To determine whether confirmation of Hb C and Hb O-Arab variants by an alternative method is required when using the Bio-Rad Variant II HPLC system.
Design:
We reviewed 48 478 consecutive hemoglobin identification test results performed on the Bio-Rad Variant II HPLC system during the period November 15, 2000 to January 15, 2003.
Setting:
Special Hematology Laboratory, Department of Pathology, Bellevue Hospital Center, New York, NY.
Main Outcome Measures:
The chromatogram patterns and retention times (RTs) for specimens containing Hb C and Hb O-Arab were analyzed. We compared the results by the HPLC method with those by the confirmatory tests (alkaline and acid electrophoresis) for both variants.
Results:
We identified 3668 cases of abnormal hemoglobin variants, including 660 cases of Hb C trait (17%), 5 cases of Hb O-Arab trait (0.1%), and 1 case of Hb SO-Arab (0.03%). A unique pattern of separation on the chromatogram for Hb O-Arab was revealed, presenting as 2 distinct peaks in 2 different manufacturer-defined RT windows, namely, D and C. The chromatogram for Hb C did not show the D window in any of the reviewed cases. The RT in the C window (C-RT) revealed a statistically significant difference for Hb C and Hb O-Arab (5.18 +/- 0.01 minutes and 4.91 +/- 0.01 minutes, respectively; P <.001).
Conclusion:
According to our review, the identification of Hb C and Hb O-Arab is accurate using HPLC methodology, as performed by the Bio-Rad Variant II HPLC system. This method can be both confirmatory and diagnostic at the same time.
