Study On The Application Of DNA Barcode-Based Signal Amplification System In The Detection Of Immunosorbent Assay And Immunospot Assay

Enzyme-linked immunosorbent assay(ELISA)and enzyme-linked immunospot assay(ELISPOT)have been widely used for immunoassay.However,these methods can only detect single signal at a time,and the sensitivity is not high enough to test the samples with low concentration,which are the major limitations to analyze the interest samples systematically.Herein,we developed fluorescence-based oligo-linked immunosorbent assay(FOLISA)and fluorescence-based oligo-linked immunospot(FOLISPOT),which utilized DNA-barcoded antibodies to provide a highly multiplexed method with signal amplification.These multiplexing approaches could provide a sequential detection of multiple targets with a single dye and a single laser channel.Besides,it was also possible for them to use multiple dyes to detect various targets sequentially.Comparing FOLISA with traditional ELISA in detecting multiple cytokines in human blood samples,we found that the sensitivity of FOLISA was higher than ELISA at 2 to 3 orders of magnitude.According to the activated immune cells in human blood,which were detected by FOLISPOT and ELISPOT,the sensitivity of FOLISPOT was also significantly higher than traditional ELISPOT.In conclusion,FOLISA and FOLISPOT based on DNA barcode amplification system were successfully constructed,which could detect multiple antigens,antibodies and cells in a single experiment with less time and higher sensitivity.