跳至主要内容

博文

目前显示的是 十一月, 2021的博文

ELISA Assay Development

  Principles The Enzyme-Linked ImmunoSorbent Assay, or  ELISA , is a technique used to detect the presence of a specific molecule in a given sample. The molecule to be detected could be an antibody or antigen. Basically, a small plastic well is coated with an antibody that binds to the antigen of interest (for example, a toxin). Sample is added to the well. If the toxin is present, it binds to the antibody and sticks to the well surface. The samples are rinsed to remove any unbound material. Another anti-toxin antibody is added. Then a tagged antibody is added; this one has an enzyme attached to one end. The substrate of the enzyme is then added. If the enzyme is there, the substrate gets converted to a colored product, and we can see it as a positive result. Procedure The surfaces of the wells in the plate are coated with a “capture” antibody. The sample is then added and any antigen present binds to the capture antibody. After washing the plates, only the antibody-antigen co...

ELISA Protocol-Elisa Experiment Standard Operating Method

  The Elisa experiment has been widely used clinically due to its high sensitivity and good specificity. However, each link in the operation has a greater impact on the detection effect of the experiment. If you are not careful, it may lead to incomplete color rendering and patterning. Wait for the result. ELISA Protocol The following step by step analysis of the factors that may affect the results of the Elisa test operation. Step 1: Specimen Selection and Preparation The most commonly used clinical specimens for ELISA determination are serum (plasma), and sometimes specimens such as saliva, cerebrospinal fluid, urine, and feces are also used for specific testing purposes. At present, the clinically used serum samples to determine the markers generally include antigens and antibodies of infectious pathogens, tumor markers, hormones, special proteins, cytokines, and therapeutic drugs. For the collection of serum samples used for hormone and therapeutic drug determination, it is nec...

Disadvantages of Indirect ELISA

  Enzyme linked immunosorbent assay (ELISA)  refers to the binding of antigen or antibody to the surface of a solid-phase carrier and maintain its immunological activity. The antigen or antibody is linked with a certain enzyme to form an enzyme-labeled antigen or antibody. This enzyme-labeled antigen or antibody retains its immune activity and enzyme activity. Common categories of ELISA: direct ELISA, indirect ELISA, sandwich ELISA (double antibody, double antigen), competitive ELISA. Disadvantages of Indirect ELISA The indirect ELISA method is similar to the direct method. The difference is that the primary antibody is not labeled with an enzyme. Instead, an enzyme-labeled secondary antibody is used to identify the primary antibody to determine the amount of antigen. The antigen is first bound to the ELISA plate, and then the detection is performed in two steps: first, the detection antibody is added to specifically bind to the antigen, and then the enzyme-labeled secondary a...

What is IND, NDA, ANDA?

  The FDA new drug review process includes two processes:   ind filing  for new drug clinical trial application and new drug application NDA application. After the applicant completes the preclinical study of the new drug, he can submit an   IND filing  to the FDA. If the FDA does not object within 30 days of receipt Applicants can conduct clinical research on new drugs by themselves. Generic drug applications are usually considered short, because such applications do not need to provide preclinical animal and clinical human data to prove their safety and effectiveness. Let’s take a look at what are IND, NDA and ANDA declarations? IND Declaration The main purpose of the IND is to provide sufficient information to prove that the drug is safe to be tested in humans and to prove that the design of the clinical program for research purposes is reasonable. The IND mainly includes phase I, II, and III clinical trial applications. The phase I and II clinical trials are...