3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
Fig. 1. Agarose gel electrophoresis of PCR products obtained
after amplification of streptococcus thermophilus DNA isolated
from yoghurt and milk drink samples by magnetic microspheres.
Lanes 1-8: yoghurt samples, lanes 9,10: milk drinks, lane 11:
positive control with purified Streptococcus thermophilus CCM
4757 DNA (c DNA = 10 ng μl –1 ), lane 12: DNA standards (100 bp
ladder), lane 13: negative control without DNA. A: 1 µl of DNA
matrix, b: 2 µl of DNA matrix
sity were detected using higher amounts of DnA matrix.
From these results it follows that the negative influence of
PCR inhibitors in tested products on the PCR course was thus
eliminated. DnA was isolated in a quality suitable for PCR.
s794
Conclusion
The method of DnA isolation from yoghurt samples by
magnetic microspheres was evaluated. Using the proposed
DnA isolation process, PCR products specific to Streptococcus
thermophilus were amplified in all samples. The results
presented here show that the simple method proposed is suitable
for the isolation of whole DnA from yoghurt and milk
drink samples, which can be used for PCR.
The financial support of the National Grant Agency for
Agricultural Research (NAZV) grant No. 1G 57053 and a
long-term research programme of the Ministry of Education,
Youth, and Sports of the Czech Republic (MSM 0021622415)
are gratefully acknowledged. We thank Mr. Ladislav Červený
for his kind language revision.
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