Meaning of Northern blot

North'ern blot'

Pronunciation: [key]
  1. a procedure for studying the activity of a specific gene, as in testing for a hereditary defect: RNA fragments in an extract of a cell population or a tissue are separated by gel electrophoresis, transferred to a filter, and then hybridized with labeled DNA or RNA derived from a laboratory-engineered copy of the gene in order to identify the size and abundance of the RNA expressed by that gene.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.