Keith Kizer, the executive director of the Nevada Athletic Commission, confirmed in an email with MMAjunkie.com that all fighters from UFC 155: Dos Santos vs. Velasquez II were tested for performance enhancing and recreational drugs.
All 24 fighters from the card tested clean, according to Kizer. The event took place December 29 from the MGM Grand Garden Arena in Las Vegas.
Typically, just the main event and a select few fighters are tested. The commission, however, decided to test everyone on the card, including new UFC heavyweight champion Cain Velasquez and former champ Junior dos Santos.