Miller's experiment sought to prove that amino acids could form on their own in primordial earth-like conditions, but it contains inconsistencies in a number of areas: By using a mechanism called a "cold trap," Miller isolated the amino acids from the environment as soon as they were formed. Had he not done so, the conditions in the environment in which the amino acids were formed would immediately have destroyed these molecules. Their destruction or transformation into different compounds through chemical reactions would have been unavoidable. In the 1980s, scientists agreed that nitrogen and carbon dioxide should have been used in this artificial environment instead of methane and ammonia. There was enough oxygen to destroy all the amino acids in the atmosphere at the time when they were thought to have been formed.