1.     What is PCR?

Polymerase Chain Reaction (PCR) is a method widely used in Molecular Biology of Genes to make many copies of a specific DNA segment in vitro. It’s the biochemist Kary Mullis who discovered PCR in the 1980s and was awarded the Nobel Prize in Chemistry for his achievements. Now, it has been developed into a common and indispensable technique used in research for a variety of applications including:

Cloning of genomic DNA or cDNA;

Mutagenesis or modification of DNA;

Assays for the presence of pathogens;

Detection of mutations;

Analysis of allelic sequence variations;

Genetic fingerprinting of forensic samples;

Nucleotide sequencing.

PCR relies on thermal cycling, which denatures and replicates the target sequence many times by employing reactants to repeated cycles of heating and cooling in order to realize DNA melting. Almost all PCR applications require a heat-stable DNA polymerase enzyme called Taq polymerase.

2.     The schematic of PCR:

To set up a PCR, some essential components are required as below:

l  The DNA template to be copied;

l  The Primers, which are short stretches of DNA that initiate the PCR reaction;

l  DNA bases needed to construct the new strand of DNA;

l  Taq polymerase enzyme which is used to add in the new DNA bases

l  Buffer to ensure the right conditions for the reaction.

A schematic of PCR could be found in Figure 2-1.

Cycle 1:

Denature: a segment of double-stranded DNA is amplified; oligonucleotides and a DNA polymerase are physically separated at a high temperature in a process called DNA melting;

Annealing: when the reaction is cooled, the primers can bind to their complementary sequences on the single-stranded template DNA, which is called annealing.

Synthesis: Raise the reaction temperatures, and Taq polymerase extends the primers and allows synthesis of new DNA.

Cycle 2 repeated as Cycle 1

…

Cycle n: These cycles of denaturing, annealing, and synthesis are repeated for many times with continued amplification of DNA.

1.     Experiment results by LB’s technology & Products

R&D requires high quality facilitating goods as well as advanced technologies. The satisfying research results only come with the superior biological solutions. To a large extent, the quality of PCR products determines whether an experiment to be successful. LB's goal is to help the users to be more successful in their research. To that end, our team of biologists, experienced technicians, and molecular experts are dedicated to the mission of providing innovative solutions and bio-products to labs and scientists all around the world.

l  DNA Extraction:

Typical results from plasmid DNA purified using the LB’s Rapid DNA product purification Kit (Spin-Columns)

Figure 3-1: Typical results of Plant genomic DNA extraction

Figure 3-2: Typical results of Human plasma genomic DNA extraction

Figure 3-3: DNA extraction from micro-tissues

l  DNA Extraction: High Specificity of RNA purification by LB’s Plant genome RNA extraction Kit (Spin-Columns)