Glass as the solid phase for enzyme immunoassays

Antigens or antibodies may be fixed to glass surfaces by heating, fixation with formaldehyde or coupling with GA to aminoalkylsilyl glass rods. Glass is not frequently used in EIA but may carry some advantages in particular situations. 

Proteins may be coupled to glass (Robinson et al., 1971 Hamagu-chi et al., 1976), details of which are given in Table 13.9. With this method the detectability in EIA, using BGase as marker, is about 30 amole (30 x 10 mole) of antigen per assay tube (1 ml), which is about 10 times better than with Sepharose 4B. The reproducibility of the technique is also greater. 

Bake pyrex glass rods (diameter 3 mm, 5 mm long at 500 C for 5 h). 

Wash the rods with 250 mM sodium phosphate buffer, pH 7.5. 

Immerse the rods in a solution of the antigen or antibody in the same buffer (2 mg/ml) for 30 min. 

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