PURPOSE: To obtain DNA fragment containing a gene of human corticotropin releasing factor, by extracting the whole DNA derived from human fetal liver, introducing the gene of human CRF to DNA fragment which is partially digested with restricted enzymes.

CONSTITUTION: The whole DNA derived from human fetal liver is extracted, partially digested with restricted enzymes Hae III and Alu I , to give DNA fragment. DNA fragment containing this gene of CRF is extremely advantageous for incidence, since parts of mRNA corresponding to protein coding region and to 3'-untranslatable region are not scissored with introns.