Cellular Senescence and Aging, Volume 181 in the Methods in Cell Biology series, highlights new advances in the field, with this new volume presenting interesting chapters on topics such as assessing polyglutamine tract aggregation in the nematode Caenorhabditis elegans, Generation of glial cell-derived neurotrophic factor (gdnf) morphants in zebrafish larvae by cerebroventricular microinjection of vivo morpholino, Methods for detection of mitochondrial reactive oxygen species in senescent cells, Assessment of cell cycle progression and mitotic slippage by videomicroscopy, The original colorimetric method to detect cellular senescence, and more. Additional sections cover Assessing microbiota composition in the context of aging, Assessing chronological aging in Saccharomyces cerevisiae, Image processing and supervised machine learning for retinal microglia characterization in senescence, Measuring telomerase activity using TRAP assays, High throughput assessment of cellular senescence, Detection of radiation-induced senescence by the Debacq-Chainiaux protocol: Improvements and upgrade in the detection of positive events, Dynamic and scalable assessment of the senescence-associated secretory phenotype (SASP), Flow cytometry-assisted quantification of cell cycle arrest in cancer cells treated with CDK4/6 inhibitors, and more.