Molecular markers and technique used for detection of liquid biopsy: Brief overview

Liquid biopsy (LB) is a minimally invasive diagnostic tool which enables early detection, monitoring, and management of variety of diseases, including cancer, autoimmune, neurodegenerative, and infectious diseases. Analysis of molecular markers such as circulating tumor cells, circulating tumor DNA (ctDNA), cell-free DNA (cfDNA), extracellular vesicles, and other biomarkers in body fluids, offers insights into disease presence, progression, and treatment response. In cancer, LB allows for continuous tumor monitoring and overcomes the challenges of traditional tissue biopsies. In autoimmune diseases, LB can detect autoantibodies and immune complexes, offering a noninvasive way to monitor disease activity and therapeutic efficacy. In neurodegenerative conditions, biomarkers such as cfDNA and extracellular vesicles in cerebrospinal fluid help with early detection and tracking disease progression. For infectious diseases, LB can identify pathogen-derived DNA or RNA, enabling rapid diagnosis and monitoring of infections. Despite its promising potential, LB faces challenges such as lack of standardization, high sample-handling requirements, and high-cost detection techniques. Future developments, including artificial intelligence, may improve biomarker detection, test standardization, and large-scale clinical application.