fragment     
 N [fragmento] fragment, fragments

N ~ gene ~, peptide ~, protein ~

~ N ~ mixture, ~ pattern, ~ size
  The fragment mixture was used to transform X.

Adj ~ chromosomal ~, filamentous ~

V ~ analyse ~, detect ~, generate ~
  A fragment was generated by X.

~ Prep ~ from | ~ of
  DNA fragments from a number of genes | a fragment of X