A dual-label time-resolved fluorescence immunoassay for the simultaneous determination of ferritin and β -microglobulin.

Background: Lymphocytic leukemia is a kind of primary malignant tumor of hematopoietic tissue. The aim was to establish a dual-label time-resolved fluorescence immunoassay (TRFIA) for the simultaneous determination of ferritin (FER) and β -microglobulin (β -MG) for the early screening and follow-up surveillance of lymphocytic leukemia.

Methods: The sandwich immunoassay was used to detect the concentration of FER, and the competitive immunoassay was used to detect the concentration of β -MG in serum. FER in serum was captured by anti- FER antibody immobilized on microtiter wells, and then banded together with another anti- FER labeled with europium(III) Eu chelate, followed by fluorescence measurement using time-resolved fluorometry (TRF). Sm labeled β -MG and β -MG samples were added to compete with a certain amount of anti-β -MG antibody, followed by fluorescence measurement using TRF. The performance of this dual-label TRFIA was evaluated using the clinical blood and compared with the commercial assays.

Results: The linear correlation coefficient (R ) of the FER and β -MG standard curves were 0.9914 and 0.9927, respectively. The sensitivity for FER detection was 8 ng/mL (dynamic range 0-1000 ng/mL), the average recovery was 100.51%; The sensitivity for β -MG detection was 1 ng/mL (dynamic range 0-1000 ng/mL), the average recovery was 101.02%. High correlation coefficients (R ) were obtained between the commercial assays (R =.9966 for FER, and R =.9897 for β -MG).

Conclusion: The present dual-label TRFIA has high sensitivity, specificity, and accuracy in clinical sample analysis. It is an effective detection method for the early screening and follow-up surveillance of the acute and chronic lymphocytic leukemia.