Abstract:
In the first part, surface plasmon resonance (SPR) technique was applied to measure the microalbumin in urine. Various combinations of capture antibody and signal enhanced antibody on the mixed self assembly monolayer (mSAM) and carboxymethyldextran (CMD) surface were compared. The most suitable combination was a monoclonal anti-human serum albumin (anti-HSA) as the capture antibody immobilized on CMD surface, providing the specificity of the surface toward HSA binding, and polyclonal anti-HSA as the signal enhanced molecule with the detection limit of 0.001 µg/mL. The amount of the HSA presence in the urine was quantified by using the four parameters fitting (4PL). The detection was in the range of 0.02 to 2.5 µg/mL of HSA in urine sample. The result from the SPR technique was quantitatively consistent with a standard turbidimetric method with coefficient of determination (R2 ) 0.94. In the second part, the application of SPR in ABO blood-typing was investigated. Anti-A, anti-B and anti-AB antibodies were immobilized on CMD surface. A red blood cells (RBCs) sample flowed through the surface using a cross-flow immobilization technique and blood group was determined via the immunological interaction between immobilized antibody and antigens on the RBCs surface. The surfaces were regenerated using 5.0 mM NaOH and can be used a minimum of 20 times. The results from blood-typings were consistent with the results obtained from standard agglutination tests. In the third part, SPR was applied for Rh (D) blood typing. Monoclonal anti-D antibody (mixed of IgG and IgM type) was covalently immobilized on CMD surface. RBCs samples flowed over the surface and the Rh blood type were determined based on the presence or absence of D antigen on RBCs surface. The optimum flow rate for D antigen detection was 10 µL/min, providing signal of Rh positive RBCs that clearly separate from Rh negative RBCs. All 44 samples of Rh blood typed by SPR were in good agreement with standard agglutination tests. In the last part, SPR was applied for ABO-Rh blood typing in one sensor chip. The suitable condition for serum grouping using immobilized synthetic blood group A and B antigen on CMD surface was studied. All ligands were immobilized on CMD as integrated platform for cell grouping, serum grouping and Rh (D) typing. The method for ABO-Rh blood typing using a single injection of 1:5 dilution of whole blood in PBST buffer was demonstrated. ABO and Rh blood were typed at the same time in 20 minutes. This technique allows the easy and convenient method for ABO-Rh blood typing with saving time and cost by the surface can be regenerated with 20 mM NaOH. The surface can be used up to 10 times.
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