work fruitlessly

基本解释

Caves were thought to be essentially devoid of life until six years ago, when the renowned University of Colorado microbiologist Norman Pace, also an avid caver, discovered a way to identify extremophile microorganisms by cloning and sequencing unique sections of their DNA. Prior to Pace's work biologists had fruitlessly tried to cultivate these microorganisms with traditional lab techniques using nutrient-rich petri dishes.
FORBES: Magazine Article