The determination of cell numbers or biomass in laboratory cultures or environmental samples is usually based on turbidity measurements, viable counts, biochemical determinations (e.g., protein and lipid measurements), microscopic counting, or recently, flow cytometric analysis. In the present study, we developed a novel procedure for the sensitive quantification of microbial cells in cultures ...

The detection of mycoplasma in milk can be performed by either culture techniques or polymerase chain reaction (PCR) based methods. Although PCR can reduce the average diagnostic time to 5 h in comparison with the several days for the isolation of the agent, there is still a need to develop methods, which could give earlier results. For this purpose, we tested the ability of flow cytometry (FC)...

We have investigated the mechanics of individual DNA strands exposed to DNA binding ligands. The interaction of these agents with individual dsDNA strands measured by optical tweezers clearly indicates the ligand-DNA binding mode. As expected, if the compound is intercalating then an increase of contour length is detected. Groove binders affect the overstretching capabilities of the formerly “n...

Assessment of cytokine expression has become crucial to understand host responses to infections as well as autoimmunity. Several approaches including Northern blot, RNase protection assay and enzyme-linked immunosorbent assay have been used for this purpose, but they are time consuming, labour intense, and relatively large quantity of the samples is usually required. Recently, a technique terme...

Cereulide-producing Bacillus cereus can cause an emetic type of food-borne disease that mimics the symptoms provoked by Staphylococcus aureus. Based on the recently discovered genetic background for cereulide formation, a novel 5' nuclease (TaqMan) real-time PCR assay was developed to provide a rapid and sensitive method for the specific detection of emetic B. cereus in food. The TaqMan assay i...

Real-time reverse transcription polymerase chain reaction (RT-PCR) methods that monitor product accumulation were adapted for the validation of differentially expressed genes. We describe a real-time quantitative PCR assay that uses SYBR Green I dye-based detection and product melting curve analysis to validate differentially expressed genes identified by gene expression profiling technologies....

The recent development of real-time PCR has offered the opportunity of sensitive and accurate quantification of mRNA levels that is crucial in biomedical research. Although reverse transcription (RT)-PCR is at present the most sensitive method available, many low abundant mRNAs are, although detectable, often not quantifiable. Here we report an improved two-step real-time RT-PCR procedure using...