Base, your source of wealth (7)

I believe the answer is:

thymine

'base' is the definition.
(one of the four bases of DNA)

'your source of wealth' is the wordplay.
'your' becomes 'thy' (I've seen this before).
'source of wealth' becomes 'mine' (I've seen this before).
'thy'+'mine'='THYMINE'

I've seen this clue in The Times.

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