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Within each group, sequenced UMIs are analyzed to determine whether they originated from the same UMI. To do this, UMIs are clustered. The UMI that has the most reads is used as the seed for the first cluster. The seed UMI is connected to all UMIs within a single edit distance that have fewer reads than it to form a cluster. Every UMI within the cluster then serves as the seed for a subsequent round of connection, again connecting seed UMIs to all UMIs within a single edit distance that have fewer reads than the seed UMI.  This process is repeated Additional rounds of connection are performed until no more UMIs can be incorporated into the cluster. The unclustered UMI with the highest number of reads is chosen as the seed for a second cluster and the same clustering procedure is repeated. This process of clustering continues until all UMIs in the group have been assigned to a cluster. 

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