How do I insert a specific string into a BioSequences DNA string?

Specific Domains
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2

Since insert! isn’t defined over these types, here is one workaround:

using BioSequences

a=dna"ATCG"

a = a[begin:1] * dna"CG" * a[2:end]

This function might be useful for repeating the task, although it returns a new sequence rather than editing one in place:

function insert_at(original, i, new)
    return original[begin:i-1] * new * original[i:end]
end