RESUMO
Objective: To establish a multiplex PCR-microarray method for detecting important enteropahogens.Methods: Uniplex and multiplex PCR were performed to obtain the best primer sets for identifying the target bacteria at species and multi-species level.Fluorescent dyes were mixed into PCR reaction to determine whether it can affect the efficiency of amplification.To improve the efficiency of microarray,a 35 pairs primer-labeling system was optimized based on the hybridization results to find the best combination to avoid false negative results.Results: Specific PCR products were all obtained using species-specific primer sets.More preferential amplification may happen when more primer pairs were added to the reaction.The hybridization results showed a positive association between the efficiency of multiplex-PCR and signal intensity.Conventional PCR yielded more products than fluorescent dyes labeled PCR.Thirty-five primers were divided into three different combinations to label target respectively,hybridization results showed a high specificity.Conclusion: Mixing fluorescent dyes into PCR may reduce the efficiency of amplification and hybridization,but may have no effect on the analysis of hybridization results.The hybridization efficiency of microarray depends on the amplification efficiency of multiplex PCR.For microarray target labeling,three primer sets could be used to avoid negative hybridization led by preferential amplification of multiplex-PCR.It indicates that the multiplex PCR-microarray method is an attractive diagnosis tool for the high-throughput identification of enteropathogenic organisms especially for multiple causative agents and epidemiological investigations.
