Avoiding stress responses

• siRNA

• • sequence
  • • • A/U 5'end
      • G/C content : 36-56%
      • avoid sites for mRNA binding proteins
      • asymmetrical 2nt 3'end more effective
  • size
  • • • 21-23 nt or 25-29nt
  • structure
  • • • A-form helix siRNA:mRNA