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Updated: May 6, 2026
Purification of a High Molecular Mass Protein in Streptococcus mutans
Published on: September 14, 2019
[A novel TaqMan® MGB probe for specifically detecting Streptococcus mutans]
Hui Zheng1, Jiu-Xiang Lin, Ning DU
1Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Objective:
To design a new TaqMan® MGB probe for improving the specificity of Streptococcus mutans's detection.
Methods:
We extracted six DNA samples from different streptococcal strains for PCR reaction. Conventional nested PCR and TaqMan® MGB real-time PCR were applied independently. The first round of nested PCR was carried out with the bacterial universal primers, while a second PCR was conducted by using primers specific for the 16S rRNA gene of Streptococcus mutans. The TaqMan® MGB probe for Streptococcus mutans was designed from sequence analyses, and the primers were the same as nested PCR. Streptococcus mutans DNA with 2.5 mg/L was sequentially diluted at 5-fold intervals to 0.16 μg/L. Standard DNA samples were used to generate standard curves by TaqMan® MGB real-time PCR.
Results:
In the nested PCR, the primers specific for Streptococcus mutans also detected Streptococcus gordonii with visible band of 282 bp, giving false-positive results. In the TaqMan® MGB real-time PCR reaction, only Streptococcus mutans was detected. The detection limitation of TaqMan® MGB real-time PCR for Streptococcus mutans 16S rRNA gene was 20 μg/L.
Conclusion:
We designed a new TaqMan® MGB probe, and successfully set up a PCR based method for detecting oral Streptococcus mutans. TaqMan® MGB real-time PCR is a both specific and sensitive bacterial detection method.
