aaaaa Immunochromatographic strip test aaaaa
 
         Immunochromatographic strip test or namely lateral flow test is a unique type of rapid test that has been developed for detecting the desired target. The strip test consists of 3 important parts which are conjugate pad, test line and control line. The conjugate pad is the area for interaction between target and detector labeled. This reaction, called test sample, flows beside the PVDF membrane via capillary action to form complex with detector at the test line. The desired target can be detected at the test line by observing the signal attached on detector. Most of detector is monoclonal antibody, however, other scaffold is applied i.e. ankyrin protein. The signal detector is attached by coloured particles, fluorescent or chemical luminescent. In our lab, we have the technology of colloidal gold attachment to any protein. Designing the lateral flow test can be generated as either competitive or sandwich assays. Most of the commercial tests are assembled based on the conjugation of colloidal gold particles to monoclonal antibodies embedded within the conjugate pad of a strip test. We have completely developed immunochromatographic strip test because of the technologies of particle attachment and protein production constructing in our lab and collaborators.
 
     
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  Colloidal gold synthesis  
 
        Here, we can synthesize the colloidal gold and attatch to any proteins. There are two methods to preparing the colloidal gold which are heat and non-heat process. We are going to develop new particle in diffent color with colloidal gold to further design the complexity system.
 
     
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  Protein synthesis  
 
        We are successful to produce a wide variety of protein since the protein expression system in our group can be performed in bacterial expression systems (Escherichia coli) and Baculovirus-insect cell as well as hybridoma cell for constructing antibody developed by our collaborator. Moreover, the protein synthesizing from above description in flask scale can be applied to large scale. The knowledge of simplex is applied to optimize condition for obtaining a large protein yield in bioreactor. Therefore, a huge amount of protein is enough for assembling to be step test.
 
     
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  Strip products  
 
        We have constructed several strip tests based on sandwich assay. Alpha thal strip is currently in global margeting which is very useful in clinical diagnosis and research study. For other strips, they are in research such as nevirapine strip test, salbutamol strip test, ankyrin strip test, HIV protease strip test. Moreover, we are going to develop new test kits with the collaborators. The below strip examples represent the principle of each kit in our lab.
 
          @ Ankyrin based immunochromatographic strip (ABIS) test for capsid detection  
 
        This ABIS test is composed of 1D4-CGC that has been previously absorbed on the conjugate pad. The monoclonal antibody clone M88 and rabbit anti-ankyrin antibodies are coated on the nitrocellulose strip at the test line and control line, respectively (A). The ABIS test involves dipping the strip into the sample to be tested. As shown, if the sample contains the capsid (C), it forms two lines, whereas in the absence of the capsid (B), it only forms a single line.
 
     
          @ PIs-IC strip test for determining HIV-PRH6 activity   
 
        Anti-MA HB-8975-CGC are adsorbed onto the conjugated pad while anti-MA G53 mAb are immobilized on the test line zone (T) and anti-mouse Igs are immobilized the control line zone (C).

(A) Proteolysis, H6MA-CA and HIV-PRH6 are incubated at 37 ºC; HIV-PRH6 recognizes the cleavage site between the MA and CA domains. Following the proteolytic reaction, H6-MA and CA are released.

(B) In the presence of HIV-PRH6, anti-MA HB-8975-CGC reacts with the free C-terminal of the cleaved H6MA, and then this complex is captured by anti-MA G53 mAb. A red-purple color at the Test and the Control line is interpreted as a positive result.

(C) In the absence of HIV-PRH6, the anti-MA HB-8975-CGC and the intact H6MA-CA move upward independently. A red-purple color at the Control line only indicates a negative result.

 
     
          @ IC test strip for the detection of Hb Bart’s (γ4)  
 
        Strip which shows the red-purple streaks at capture and control lines will be interpreted as positive result. Otherwise, negative result demonstrates red-purple streak only at control line. Arrows indicate the direction of sample diffusion.
 
     
          @ IC test strip for the detection of salbutamol  
 
        The schematic diagram shows the areas where anti-SALB-CGC, SALB-BSA and goat anti-rabbit IgG are immobilized. The reactions that occur on the IC-test strip in the absence of salbutamol (Case 1), and in the presence of salbutamol (Case 2) are shown. A red color appears at the test line and/ or control line, depending on the presence of salbutamol in sample.
 
     
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