Size of exons and introns?

Keith Robison robison1 at
Thu Oct 1 11:25:32 EST 1992

naffara at (Dr. N.A. Affara) writes:

>This may have been asked before....

>Does anyone know the maximum, minimum, (if any) and average size of exons
>and introns in human DNA?

>The reason I am asking is that I am trying to design PCR primers from 
>cDNA sequence and I want to have some idea of the exon/intron sizes.

>(E-mail naffara at

	I posted something a while back on the subject -- you might try
the archives.  The largest exon known is in apolipoprotein B and is
over 7 Kb.
	If memory serves me, human introns smaller than 75 bp are
very rare, but the largest ones can be enormous (10s of Kb, probably
some in the 100s of Kb).

Keith Robison
Harvard University
Department of Cellular & Developmental Biology
Department of Genetics / HHMI

robison at 

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