CD40L (Cluster of differentiation 40 Ligand) and CD40 (Cluster of differentiation 40) are a pair of complementary co-stimulatory molecules, taking part in specific immune response system in body. They play important roles in antigen presentation and immune responses, the abnomality of either CD40L or CD40 will cause a series of downstream reactions CD40 is a member of the TNFR superfamily, which is a type I transmembrane protein mainly expressed in B cells. CD40, known as the APC (antigen presenting cells) co-stimulatory protein, is essential for the activation of APC. CD40 can combine with TRAF1, TRAF2, TRAF3, TRAF5, TRAF6 and TTRAP. CD40L was originally found on the surface of acti......

Recombinant protein is produced by transferring the target gene to a vector and expressed in host cells. It plays important roles in signal transduction, pharmaceutical development and scientific research. Below is an introduction on production process of recombinant proteins. 1.Gene amplification （1）Primers synthesis Primers are designed by analyzing the gene sequence as well as the protein structure. Trans-membrane area and complex secondary structures should be avoided. Meanwhile, it is preferred to choose N or C terminal sequence and the evaluation of the primers should be high. Search restriction sites and proper vector. （2）Gene cloning and identification of recombinant co......

Sandwich CLIA is a kind of detection method combined double antibdoy sandwich method with chemiluminescence detecion method. It regualrly includes lots of steps, which are shown below. At first, the microtiter plate has been pre-coated with an antibody specific to analyte. Then, standards or samples are added to the appropriate microtiter plate wells, the analyte in standards and samples will bound to the immobilized Ab. Next, biotin-conjugated antibody is added and binds to the analyte absorbed on the plate. The complex of two antibodies and analytes in the wells act as a “sandwich” structure. After the unbound biotin-conjugated antibody is washed away, avidin-conjugated H......

Currently, prokaryotic and eukaryotic expression system are the most common used protein expression systems. And eukaryotic expression system contains yeast, mammalian and insect cell expression system, . The prokaryotic expression system is famous for its economic and efficient, but it is lack of post-translational modification. Hence, to some extent, proteins expressed by this system regularly do not possess bio-activity. The insect cell expression system involves the use of baculovirus, so it also has its own limits. Yeast expressed proteins have high level of expression, and they are easy to purify, but the proteins are also prone to degrade and the expression processes are hard......

Copeptin (CPP), is a part of C-terminus in arginine vasopressin (AVP) (Figure 1), a new biological marker in the recent research. Many studies show that it plays an important role in early diagnosis and prognosis of cardiovascular disease, pulmonary infection, etc. The latest research shows that copeptin combined TnI shows great value in early diagnosis of acute coronary syndrome. Why is peptide is so special? How about its structure and function? Copeptin is a kind of leucine-rich glycopeptide, AVP-derived, comprised of 39 amino acids. Until now, its biological function is not very clear, some studies suggest that it plays an important role in the processing of AVP precursor process......

Immunohistochemistry (IHC) is also called as immunocytochemistry (ICC). It is a immunological method for qualitative and quantitative detection, as well as location of antigen in situ in cells of a tissue section, using specific and labeled antibody. It bases on the reaction of antigen and antibody, together with the color reaction of histochemistry. It skillfully combines the specificity of immunological reaction, the visibility of histochemistry and the sensitivity of molecular technology. For antigens (such as protein, peptide, enzyme, hormone, pathogen and receptor, etc) can be detected in cellular or subcellular level by visualization and amplification using microscope, it provide......