Matrix‐assisted Laser Desorption Ionization Mass Spectrometry for Detection of α/β‐Chain Changes From Human Hemoglobin: An Exploratory Study

In this work, we developed a matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) method to directly analyze human whole blood samples. 1.0 µL of whole blood samples and 1.0 µL of optimized organic matrix were directly loaded onto the sample plates for MALDI‐TOF‐MS detection. A total of 59 whole blood samples were investigated in this work, including 23 healthy control samples, 28 α‐globin gene triplication carriers with α‐chain repetition, and eight deletional hemoglobin H disease (HbH) patients with α‐chain deficiency. Human hemoglobin (Hb) chains with high signal‐to‐noise were directly observed. It is found that there is a change in signal ratios of α/β‐chains of Hb from blood samples in thalassemia subtypes by comparing the ratios obtained from healthy blood samples. Analytical variability ( n = 6) of signal ratios of α/β‐chains was found to be 3.33%–12.86% (intra‐day), 4.02%–13.39% (inter‐day), and 6.41%–15.32% (inter‐laboratory), respectively. Furthermore, the results were validated using different MALDI‐TOF MS approaches. Our results suggest that α/β‐chains ratios of Hb could be an indicator for investigating thalassemia by MALDI‐TOF‐MS.