BY SERUM

Blood samples allow for the detection of Cotinine in blood plasma, though a blood sample requires a great deal more processing than urine or saliva samples. The blood sample is first centrifuged to separate the blood cells from the plasma, and heavy proteins are then precipitated out. The test tube is centrifuged a second time and then placed in an evaporator to remove any remaining liquid; the dry proteins, including Cotinine, are dissolved using methyl alcohol. Once more, the test tube is centrifuged to separate out any remaining heavy proteins, and the fluid is poured off and used for analysis.