The Guo lab at Arizona State University is focused on single cell in situ systems biology. This presentation outlines their efforts in developing a highly multiplexed single cell analysis approach, quantifying the identities, positions, and abundance of a large number of genomic loci transcripts and proteins in single cells from intact tissues in situ. This approach aimed to enhance understanding of brain function, tumour progression, and biomarker discovery.
Guo introduced a reiterative immunofluorescence method, where chemically cleavable linkers were inserted between fluorophores and antibodies. This allowed multiple cycles of staining and imaging without losing signal integrity, enabling the quantification of a large number of different proteins in the same set of cells. The method demonstrated high cleavage efficiency, with over 98% of original fluorescent signals removed in under 30 minutes, and subsequent staining remained effective.
The research addressed challenges in visualising biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues, which often had high autofluorescence and damaged biomolecules. To overcome these challenges, Guo's team developed a new method involving conjugating horseradish peroxidase (HRP) to antibodies, significantly amplifying signals and enabling the detection of low-expression proteins in challenging samples.
Guo's team expanded their research to analyse various cell types and their interactions in neurodegenerative diseases. This aimed to better understand disease mechanisms and identify biomarkers for patient stratification. The HRP-based method amplified signals by about two orders of magnitude compared to conventional immunofluorescence, making it possible to visualise low-expression proteins in FFPE tissues.
The presentation highlighted the unique advantages of the HRP-based approach, including high sensitivity and accuracy in detecting biomarkers. Guo's team applied this method to clinical samples, successfully staining and quantifying a large number of different proteins and RNA molecules in patient biopsies. The research demonstrated the potential of this approach to identify better biomarkers for diagnosis, treatment monitoring, and drug target discovery.
In conclusion, Jia Guo's presentation showcased innovative methodologies for single-cell spatial proteomics and transcriptomics analysis, addressing challenges in clinical applications and paving the way for future research in neurodegenerative diseases.
