The microarray technique for proteins was developed by adopting the same microarray technology initially used for genomic analysis of DNA and RNA. The microarray technique allows multiple solid phase enzyme immunoassays in which the recombinant proteins or allergens are immobilized on a solid phase and the serum is incubated with these proteins under standardized conditions. The antibodies present in the serum bind to different allergens or antigens. After adequate washings and interaction with specific ligands, the intensity of the signal is finally evaluated by colorimetric or fluorescent detector. With this technique, multiple samples and multiple antigenic components can be determined in a single application, significantly reducing the volume of reagents used. In this specific case, suitably prepared glass supports with thin nitrocellulose films are used in order to allow a strong and non-specific interaction between surface and proteins. The proteins are deposited at very close distances creating regular matrices. Then follows the development and calculation step for the quantification of the specific protein-ligand interaction.
Microarray printing in process, completing of its the development and quantification.
For the preparation of the microarrays, it is essential to have an extremely precise deposition system because the distances between the spots are less than 500um (it could be lower than this value). Volume management must also be accurate and reproducible considering that the volumes to be managed are of the order of the nanolitre.
For this purpose, the M2 iONE-600 spotters offer a high degree of accuracy and reliability. Furthermore, by means of PDMD, different volumes can be easily managed, and cross-contamination processes are avoided since the deposition system does not foresee any direct contact with the surface of the microarray.