抗體是免疫系統(tǒng)對進入體內(nèi)的外來分子做出反應而產(chǎn)生的宿主蛋白。這些外來分子被稱為抗原。由于抗體能與相應的抗原發(fā)生特異性結(jié)合反應，因此特異性抗體是免疫學實驗中常用的試劑，不僅對于抗原的分析鑒定和定量檢測極為重要，而且廣泛應用于臨床疾病的診斷、治療和預防中。在免疫學檢測中應用的主要抗體是多克隆抗體和單克隆抗體，多克隆抗體常用免疫動物的方法獲得，而單克隆抗體則采用雜交瘤技術(shù)制備。

antibody, also called immunoglobulin, a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen. Antibodies recognize and latch onto antigens in order to remove them from the body. A wide range of substances are regarded by the body as antigens, including disease-causing organisms and toxic materials such as insect venom.