Evaluation method for asymmetric uncertainty of quantitative polymerase chain reaction measurements of deoxyribonucleic acids with low copy number.

Recently, in food safety and various other fields, qualitative and quantitative gene analysis using real-time polymerase chain reaction (PCR) method has become increasingly popular. The limit of detection (LOD) and quantifiable range for these measurements depends on the range and precision of DNA calibrators' concentrations. Low-copy-number nucleic acid reference materials with low uncertainty produced by an inkjet system have been developed to allow for precise measurements in a low-copy-number region.

Novel Bioprinting Application for the Production of Reference Material Containing a Defined Copy Number of Target DNA.

Nucleic acid amplification methods, such as polymerase chain reaction (PCR), are extensively used in many applications to detect target DNA because of their high sensitivity, good reproducibility, and wide dynamic range of quantification. However, analytical quality control when detecting low copy number target DNA is often missing because of a lack of appropriate reference materials. Recent advances in analytical sciences require a method to accurately quantify DNA at the single molecule level.

Improved rapid and efficient method for Staphylococcus aureus DNA extraction from milk for identification of mastitis pathogens.

A rapid and efficient DNA extraction method was developed for detecting mastitis pathogens in milk. The first critical step involved cell wall disruption by bead-beating, as physical disruption using beads was more effective for DNA extraction from Gram-positive bacteria, such as Staphylococcus aureus, than enzymatic disruption using proteinase K. The second critical step involves the use of acetic acid and ammonium sulfate in the purification process, as these reagents effectively and efficiently remove the lipids and proteins in milk.