Are UMIs not actually unique?

Not strictly, but unique enough. The distribution of UMIs should ideally be uniform so that the chance of any two same UMIs capturing the same transcript (via different amplicons) is small. As barcodes have increased in size, the number of UMIs has also increased allowing for UMIs to reach more or less the same numbers of transcripts.

Still have questions?

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{% snippet  topics/transcriptomics/faqs/umi.md %}