prime-seq is a simple and open RNA-seq method, which can be easily established in most research labs or facilities. Based on two of the most sensitive single cell RNA-seq methods available, namely smart-seq2 and mcSCRB-seq (Picelli et al. 2013; Bagnoli et al. 2018), prime-seq is an adaptable, affordable, robust, and high-throughput option. Additionally, prime-seq can be used on a wide range of model organisms, from apes to zebrafish, and many in between.