VITRO

Set to 4 different clues across 5 published puzzles, most often “In ___ fertilization” — The New York Times, Wednesday, 13 April 2011.

5 letters

Every clue on record, most used first

In ___ fertilization2 times
The New York Times — Wednesday, 13 April 2011
Not natural, in a way, after "in"once
The New York Times — Thursday, 29 October 2009
Artificial, after "in"once
The New York Times — Sunday, 10 August 2003
In _____ (from a lab)once
The New York Times — Saturday, 15 April 1995