快速、准确地在血液和骨髓中识别白血病细胞对于临床诊断至关重要。提出了一种将传统细胞形态学与免疫表型分析相结合的综合技术，以提高白血病的诊断效率。由于具有高的光稳定性、生物相容性和信噪比，上转换纳米颗粒（UCNPs）作为发光标记引起了大量研究关注。为了实现同时测定，将NaYF4:Yb,Er UCNPs与CD38抗体耦合，构建了能与弥漫性大B细胞淋巴瘤（DLBCL）细胞结合的免疫荧光探针，随后进行了被广泛应用于临床工作的Wright染色，用于形态诊断。进一步优化了实验条件，如培养基、切片制备方法、抗体剂量、孵育时间等。细胞形态学和免疫标记可以同时观察到，并且其简单操作使之成为临床诊断的可能性。所开发的免疫标记分析可以实现DLBCL细胞计数，具有高的重复性和稳定性，检测限为1.54个细胞/片（>3σ/秒）。此外，该方法还实现了真实血液和骨髓样本的分析，并且结果与临床诊断一致。总体而言，这种策略可以在简单的实验室培训后进行，并在白血病分类、诊断验证和差异诊断中具有前景的生物医学应用。© 2023 Chen et al.

Accurate, sensitive, and rapid identification of leukemia cells in blood and bone marrow is of paramount significance for clinical diagnosis. An integrative technique combining traditional cytomorphology with immunophenotyping was proposed to improve the diagnostic efficiency in leukemia. On account of high photostability, biocompatibility, and signal-to-background ratio, upconversion nanoparticles (UCNPs) as luminescent labels have drawn substantial research scrutiny in immunolabeling.To achieve simultaneous determination, NaYF4:Yb,Er UCNPs were coupled with CD38 antibodies to construct immunofluorescence probes that were developed to bind to diffuse large B cell lymphoma (DLBCL) cells, followed by Wright's staining that has been widely used in clinical work for morphological diagnosis. Further, the experimental conditions were optimized, such as medium, slice-making method, antibody dosage, incubation time, etc.The cell morphology and immunolabeling could be observed simultaneously, and its simple operation rendered it a possibility for clinical diagnosis. The developed immunolabeling assay could achieve DLBCL cell counting with high reproducibility and stability, and the detection limit was as low as 1.54 cell/slice (>3 σ/s). Moreover, the proposed method also realized real blood and bone marrow sample analysis, and the results were consistent with the clinical diagnosis.Overall, this strategy can be carried out after simple laboratory training and has prospective biomedical applications in leukemia classification, diagnosis validation, and differential diagnostics.© 2023 Chen et al.