Possible Clues:

• Unable to reproduce
• Ineffective steps taken to protect top female
• Fresh from the autoclave
• Set off to get one's goat? It's non-productive!
• Disinfected the leister before use
• Fruitless, like Hamlet's goodly frame
• Not producing offspring
• Unyielding
• Uncontaminated, set free over bug
• Tries out failed service largely devoid of ideas