Chell, documented as Test Subject #1 but previously as #1498, is the silent protagonist of Portal and in the single-player campaign of Portal 2, and was an Aperture Science Test Subject.
Although Chell's origins are unknown, she was definitely among the people present during GLaDOS' activation in 200-, as GLaDOS locked down the facility immediately afterward; information revealed in Portal 2 implies that Chell was the child of an Aperture scientist because one of the "Bring Your Daughter To Work Day" science projects is signed by her. According to the psychological profile in her personnel file, Chell is "abnormally stubborn" and refuses to give up, no matter how daunting the challenge. Originally, she was rejected as a test subject, but Doug Rattmann altered the testing order, having correctly guessed that Chell's extreme tenacity might allow her to defeat GLaDOS. Chell's Test Subject Application Form states that she refused to answer the essay question and instead answered in binary. The binary can be translated to "The cake is a lie."
|Aperture Science Robot Worker ● ATLAS ● Chell ● GLaDOS ● Mel|