DNA microarray synthesis by using PDMS molecular stamp (II) - Oligonucleotide on-chip synthesis using PDMS stamp

Based on the standard phosphoramidites chemistry protocol, two oligonucleot ides synthetic routes were studied by contact stamping reactants to a modif ied glass slide. Route A was a contact coupling reaction, in which a nucleo side monomer was transferred and coupled to reactive groups (OH) on a subst rate by spreading the nucleoside activated with tetrazole on a polydimethyl siloxane (PDMS) stamp. Route B was a contact detritylation, in which one nu cleoside was fixed on the desired synthesis regions where dimethoxytrityl ( DMT) protecting groups on the 5'-hydroxyl of the support-bound nucleoside w ere removed by stamping trichloroacetic acid (TCA) distributed on features on a PDMS stamp. Experiments showed that the synthetic yield and the reacti on speed of route A were higher than those of route B. It was shown that 20 mer oligonucleotide arrays immobilized on the glass slide were successfull y synthesized using the PDMS stamps, and the coupling efficiency showed no difference between the PDMS stamping and the conventional synthesis methods .