ELISA Research FAQs

This indicator measures all subtypes of IFNα, that is, total IFNα. The standard is not a mixture of all subtypes, but human IFN-alpha 2a (recombinant protein, expression system: HEK293 cells). However, since the homology of the 15 IFN-α subtypes in humans is as high as 80%, the antibodies used in our kit can recognize all subtypes, and this kit has been verified for different subtypes of IFN-α, which can be detected.

Since the antibodies in the kit recognize activated TGF-β, and TGF-β is a disulfide bond linked by two identical or similar 12.5kDa subunits of molecular weight. The study of human TGF-β cDNA sequence showed that the 112 amino acid residues of the monomer TGF-β were cleaved from the carboxyl terminal by a precursor molecule (per-pro-TGF-β) containing 400 amino acid residues. The N-terminal of per-pro-TGF-β contains a signal peptide, which is cleaved before secretion to become an inactive polypeptide chain precursor (pro-TGF-β). The n-terminal part of the amino acid residue is removed by changing the ionic strength, acidification or protease hydrolysis, and the remaining carboxyl terminal part forms an active TGF-β. A variety of cells in the body can secrete TGF-β in an inactive state. In vitro, the inactive TGF-β, also known as latency associated peptide (LAP), can be activated by acidification. In vivo, the acidic environment can be present near fractures and healing wounds, and the cleavage of the protein itself can cause the TGF-β complex to become activated TGF-β. In general, tissues with active cell differentiation often contain high levels of TGF-β, such as osteoblasts, kidney, bone marrow, and fetal liver hematopoietic cells. Therefore, no additional activation processing is required for tissue sample testing.

These two kits can be used for the detection of your cell supernatant. However, ELISA detection of cell supernatants is affected by factors such as media components, cell growth, and external drug stimulation conditions, and it is recommended that you conduct a preliminary experiment before the formal experiment. Gelatin enzyme spectrometry uses the reversible combination of SDS and MMPs in the sample to separate MMP-2 and MMP-9 in the sample, and then restores the activity of both through the bivalent metal ion buffer system. This test method is specifically aimed at the activity detection of MMP-2 and MMP-9. ELISA detects the content (that is, concentration) of the tested substance through the binding reaction of antigen and antibody, that is, captures the MMP-2 and MMP-9 of the sample through the specific antibodies of MMP-2 and MMP-9. The experimental principles of the two are different, and the activity of MMP-2 and MMP-9 cannot be detected by ELISA.

VEGFA (VEGF) has a variety of subtypes (shear isomers), of which VEGF165 is the most abundant and effective VEGFA subtype (P15692-4), VEGF165 kit detection is the VEGF165A you mentioned, and VEGF165B is another shear body (P15692-8).

Collagen (COL1) consists of three peptide chains, two of which are α(Ⅰ) chain, COL1α1, and one α(Ⅱ) chain, col1α2. The homology between the two was 60.396%, and there was no obvious cross-reaction.

uPAR is a membrane binding receptor for uPA, also known as urokinase and hyaline. suPAR is caused by the splitting and release of membrane-bound uPAR and is the soluble form of uPAR. The kit measures total uPAR, both in membrane form and in soluble form.

In mammals, the APP gene is located on chromosome 21 and has a total of 8 subtypes, whose subtypes generally contain 365~770 amino acid residues. The most common are APP695, APP751, and APP770, of which APP695 is highly expressed in the central nervous system. APP is a type I transmembrane glycoprotein with a molecular weight of about 110~130 kDa, with a large extracellular (amino terminal) domain and a small cytoplasmic tail region (intracellular carboxyl terminal). APP is metabolized mainly through two pathways: amyloid (β) pathway and non-amyloid (α) pathway. The amyloid pathway is that APP is cleaved by β-secretase into sAPPβ and a C-terminal fragment containing 99 amino acids. The latter is further cleaved by γ-secreting enzymes into Aβ and ACID, and the Aβ generated by this pathway accounts for 90% to 95% of the total Aβ, including two types of Aβ1-40 and Aβ1-42, of which the content of Aβ1-40 is higher, but Aβ1-42 has A strong hydrophobic effect, its toxicity is greater, and it is easy to polymerization. These Aβ fragments accumulate in mitochondria, lysosomes, and the endoplasmic reticulum, causing these suborganelles to malfunction. In the non-starchy source pathway based on alpha secretase, the alpha secretase cuts APP into sAPP and a C-terminal fragment containing 83 amino acids, which is then cut by gamma secretase to produce P3 and ACID, but these small fragments are cleared by neurons. The mutation of APP gene can cause abnormal protein expression or hydrolysis change, thus affecting the content and composition of Aβ in cells. Aβ mainly exists in the brain in the form of Aβ40 and Aβ42, and the content of Aβ42 is low (< 10%), but easy to aggregate, and then fibrosis and deposition, thus forming a diffuse senile plaque, which is also one of the main pathological characteristics of AD. Moreover, Aβ produced by APP after cleavage by β- and γ-secretory enzymes on the cell membrane can cause oxidative stress, calcium ion inflow, and then damage mitochondria, leading to nerve cell disorders, activation of apoptosis-related proteins and factors, and finally start the apoptosis process of cells. In addition, Aβ can also indirectly cause neuronal apoptosis by causing inflammation in the brain and neurofibrillary tangles, which is an important reason for the formation and development of AD.

Most substances can be relatively stable under freezing conditions, but it is recommended to use newly collected samples for testing to obtain more accurate results. There are three kinds of methods for PAF detection: ① biological detection method; ② Physicochemical method; ③ Immunological methods. ELISA assay recommends adding 1mM TPCK or TLCK to the plasma sample to inhibit the activity of PAF-AH.

These two belong to different types of prostaglandins. Prostaglandin E2 (PGE2) is the most abundant prostaglandin and is produced by the action of prostaglandin E synthetase on prostaglandin H2(PGH2). Prostaglandin D2(PGD2) is another prostaglandin produced by hematopoietic and lipoprotein prostaglandin D synthase (hPGDS and lPGDS) acting on prostaglandin H2(PGH2). In addition, the two have different receptors and different areas of study. PGE2: Mainly studies gastrointestinal smooth muscle PGD2: Studies allergic diseases such as asthma

We recommend that you refer to the cell sample treatment in the instructions instead of using 0.1M HCl for cell lysis. In theory, 0.1M hydrochloric acid can only change the permeability of cells and cannot lyse cells. At the same time, the introduction of strong acids will lead to the degeneration of proteins, which will affect the binding of antigens and antibodies, and change the pH value of the ELISA experimental system, and ultimately affect the experimental results.

Platelet has a specific morphological structure and biochemical composition, and has a relatively constant number in normal blood. It plays an important role in physiological and pathological processes such as hemostasis, wound healing, inflammation, thrombosis and organ transplantation rejection. Platelets are found only in mammalian blood. There is no fasting requirement when we test the serum plasma of normal rats for thrombatin. According to the situation in the literature, the thrombopoietin in serum plasma of rats was generally detected 24h after administration, and the requirement of fasting in rats was not mentioned. It is suggested that you can make reference selection according to the experimental purpose and literature.