MAPseq2: a sensitive and cost-effective barcoded connectomics method

The barcoded connectomics tool MAPseq enables highly multiplexed projection mapping of individual neurons by translating neuroanatomy into a format solvable by DNA sequencing. Here we present MAPseq2, a user-friendly protocol with up to ∼10-fold increased sensitivity and ∼10-fold decreased cost compared to the current state of the art. As MAPseq workflows are used across a range of barcoded connectomics methods, including BARseq, BRlCseq, and ConnectlD, all improvements in MAPseq2 directly transfer to these technologies.