Lab in a tube: Isolation, extraction, and isothermal amplification detection of exosomal long noncoding RNA of gastric cancer.

Tumor-derived exosomes that inherit molecular information on parental cells hold great promise for cancer diagnostics. Currently, two main technical challenges, time-consuming and labor-intensive isolation of exosome and nucleic acid extraction with limited recovery that have restricted the detection of ultralow abundance exosomal nucleic acids. Here, we proposed a simple, efficient and "lab in a tube" system for the detection of exosomal nucleic acids, which fully integrated exosomes enrichment using immunomagnetic beads (IMB) (10 min), fast exosomes lysis based on NP-40 lysate (5 min) and sensitive loop-mediated isothermal amplification (LAMP) in a tube. This method was demonstrated by detecting two exosomal long noncoding RNA biomarkers of gastric cancer (HOTTIP and lncRNA-GC1) with a dynamic detection ranging from 300 ng/μL to 10 ng/μL, and the detection limit of LAMP was 10 ng/μL. Additionally, this platform exhibited good performance in the analysis of exosomal HOTTIP RNA directly in human serum samples, which has the potential for detection of low-abundance exosomal nucleic acid biomarkers from cancers.