With more widely application of antibiotics in clinical practice and discovery of new viruses such as SARS and H7N9, new problems have cropped up. Due to untypical clinical symptoms and limited experience of doctors, diagnosing diseases with similar symptoms becomes difficult. Especially for bacterial infections and non-bacterial infections, their treatments are totally different. Once misdiagnosis occurs, the best treatment time might be missed. That would lead to serious consequences such as disease deterioration. Therefore, how should we judge whether it is bacterial infection or non-bacterial infection? Researchers found that, PCT (procalcitonin) is a kind of special protein, its ......2015-09-23

The aim of molecular cloning vector construction is to obtain target proteins. E. coli, yeast, insect, plant and mammalian cell expression systems are common expression systems. E. Coli expression system is the most popular one with many advantages such as the identified genetic background, simple operation, high yield, low price and so on. Separation and purification of recombinant protein is the base of developing and producing proteins, antibodies and Elisa kits.Common purification methods include ion exchange chromatography (IEX),Hydrophobic interaction chromatography (HIC), size exclusion chromatography (SEC) and electrophoresis, etc. The purity, reproducibility, stability and cos......2015-09-07

Autophagy, proposed by Ashford and Porter in 1962 after they found the "eat themselves" phenomenon within cells, refers to part of cytoplasm from no ribosome attached district of rough endoplasmic reticulum, which was embed by bilayer membrane. The cytoplasm and the organelles, and protein and the other components need degradation formed autophagosome. The autophagosome and lysosome merged and formed autophagosome-lysosome complex, the complex will degrade all the embed content. In this way, the metabolism demand of the cells will be met and some organelles will be updated . Currently autophagy is one of the most hottest topics in life science area following apoptosis ,accord......2015-09-07

The assay principle of Competitive inhibition Elisa: coat specific antibody to solid carrier, then add antigen to be tested(standard and sample) and biotin-labeled antigen(detection reagent A). The tested antigen and biotin-labeled antigen competitively binds to immobile antibody. After incubation,the unbounded conjugate is washed off. Next, Horseradish Peroxidase (HRP)conjugated by avidin is added, the substrate solution TMB is added after incubation and washing.. TMB becomes blue under catalization of peroxidase, and finally turns to yellow after addition of acid. The higher concentration of tested sample is, the inhibition for bound of labeled antigen and antibody will be more obvio......2015-08-12

The stability of ELISA kit may refer to the ability to maintain the quality and efficiency of the kit during the shelf life defined by the Manufacturer. According to different experimental purpose and condition, Stability tests can be divided into accelerated stability tests and long-term stability test. The accelerated stability tests，is normally performed at 37℃ to accelerate the chemical or physical reaction of biological reagents in the kit. And then the stability of the kit is determined. Since many unexpected factors may exist during the transportation or storage, the stability of the kit under such conditions can be estimated by the accelerated stability test. And it can be......2015-08-12

For a sandwich ELISA test, the microtiter plate has been pre-coated with an antibody specific to analyte. Standards or samples are then added to the appropriate microtiter plate wells and the anaylte present is bound by the immobilized Ab. Next, Biotin conjugated to Detection Ab (Detection reagent A) is added and binds to the analyte absorbed on the plate. The binding of two antibodies and analytes in the wells act as a “sandwich” structure. After the unbound biotin conjugated to Detection Ab are washed away, avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After the TMB substrate solution is added and development is complete......2015-08-12