
Cardiolipin (CL) is a unique phospholipid with a very interesting chemical and specific ultrastructural characteristics. It is a highly acid dimer of phosphatidylglycerol (PG) and phosphatidic acid (PA), containing four acyl chains; three glycerols and two phosphate headgroups. Due to deprotonation of one of these phosphate groups, cardiolipin is negatively charged in physiological pH [1,2].
Cardiolipin (CL) is known as mitochondria-specific phospholipid since it is almost exclusively biosynthesized and located in the inner mitochondrial membranes. The name “cardiolipin” is derived from fact that it was first found and isolated from animal heart. Cardiolipin is considered to be intimately linked to mitochondrial bioenergetic process. It plays a functional role in mitochondrial membrane stability and dynamics, interacts with a number of inner mitochondrial membrane metabolite carriers, enzymes and proteins. During apoptosis in presence of H2O2, CL-bound Cytochrome c catalyzes the peroxidation of cardiolipin, releasing Cytochrome c, which is a death-inducing protein. CL peroxidation and depletion have important implications to age-related mitochondrial dysfunction, resulting in a number of pathophysiological conditions, such as hypo/hyperthyroid states [3-7], heart ischemia–reperfusion [8-12], nonalcoholic fatty liver disease [13], diabetes [14,15], Barth syndrome [16,17] and aging [18-21]. According Birk et al. [22], the main functions of cardiolipin are: “(i) to support spatial organization of mitochondrial cristae; (ii) to create the proton trap necessary for sustaining the proton gradient and ATP synthesis by the F0F1 ATP synthase; (iii) to act as a scaffold for assembly of respiratory complexes and super-complexes to facilitate optimal electron transfer among the redox partners.”
Extensive studies [23-29] of pharmacological, toxicological, and therapeutic effects have shown that the incorporation of doxorubicin in cardiolipin liposomes improved the antitumor activity of doxorubicin, while the histopathologic lesions in cardiac tissue of mice significantly decreased. It has been reported that cardiolipin-containing liposomes have lower (at least 2-fold lower than that observed with conventional doxorubicin) cardiotoxicity associated with doxorubicin by altering the pharmacokinetics and tissue distribution of the drug in mice [29]. Also, it has been indicated that cardiolipin provides two types of binding possibility for drugs; one mostly exposed at the surface, and the other deeply buried in the membrane [30,31]. Hence, the cardiolipin-liposomes has been suggested as a convenient carrier for doxorubicin delivery to increase the therapeutic index of the drug [23].
Cardiolipin is a negatively charged lipid. Cellsome® made from cardiolipin lipid catalog containing many different types of saturated and unsaturated cardiolipin based liposomes made from 0.5 up to 100 percent of cardiolipin.


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1、直接竞争,标记抗原,与检测样品中的抗原竞争抗体。
2、间接竞争,标记抗体,固相抗原与液相抗原(样品)竞争标记抗体。
3、定义
间接竞争法的模型:包被抗原,用HRP-抗体与样本一起加入。样本中的Ag与Solid-Ag竞争HRP-Ab,固相吸附的HRP-Ab与样本中的Ag浓度成反比。
直接竞争法的模型:包被抗体,用HRP-抗原与样本一起加入。样本中的Ag与HRP-Ag竞争Solid-Ab,固相吸附的HRP-Ag与样本中的Ag浓度成反比。
4、竞争法的理论基础:是限量抗体。只有在限量抗体基础上,两种抗原才会形成竞争关系。
5、、间接竞争法具备较高灵敏度原因。
直接竞争法里,标记抗原与待测抗原均是液相,与抗体的结合机会是一样的,例如有1份标记抗原与1份待测抗原竞争1份抗体,那么有50%的标记抗原能与抗体结合,所以标记抗原的相对结合率为50%。间接法里,固相抗原与抗体的接触面积较小,固相抗原与待测抗原的结合抗体机会是不平等的,接近顺序饱和法,即只有与待测抗原结合剩余的抗体才会与固相抗原结合,同样有1份固相抗原与1份待测抗原竞争1份抗体时,基本上抗体会被待测抗原中和掉,与固相抗原结合的抗体非常少。固相抗原的相对结合率为0%。因此,间接法的抑制曲线斜率会大于竞争法。
因为抑制率越大则斜率越大,从而灵敏度越大。(假设零管变异5%,以两倍SD为灵敏度限,则为90%相对结合率,则间接法可以在较低的待测抗原浓度达到这一相对结合率,因此灵敏度要高。)
在进行系统放大时,间接法一般可以使用酶标二抗。因为二抗可以针对抗体的多个部位,所以存在放大效应,从而能提高间接法的灵敏度。直接法一般难以进行放大,常用的有生物 素化抗原与酶标亲和素,但模式上似乎不存在放大效应。
6、间接法的高灵敏度难以实现的原因:
双抗体 夹心的免放(IRMA)模式刚出现时,也被模型证明灵敏度优于竞争法的放免(RIA),原因也是较大的斜率,但是IRMA的高灵敏度一直到单抗发展后才得以实现。
采用抗-HBe抗体包被反应板,加入校准品及被测样本,同时加入定量HBeAg中和抗原,经过振荡孵育,洗板后再加入铕标记的抗-HBe,若标本中抗-HBe浓度高,HBeAg将被大量中和,使最后形成的抗-HBe-HBeAg-铕标记抗-HBe复合物减少。增强液(β-NTA)将标记在抗体上的Eu3+解离到溶液中,Eu3+和增强液中的有效成分形成高荧光强度的螯合物,荧光强度和样本中的抗-HBe浓度成反比。