Back to the Basics
These nucleotides are pyrimidines.
What are cytosine and thymine?
This reagent is responsible for chelating the Mg2+ ions, which stabilizes the DNA molecule.
What is EDTA?
Hair is best sampled for forensic DNA analysis when it is in this phase.
What is anagen?
These conditions make qPCR quants less reliable.
What is inhibition, bad standards, and/or degradation?
Improper storage technique, like storing something damp or in a plastic bag, leads to this on DNA evidence.
What is degradation?
This type of bond is formed between bases and make of the "ladder" structure of DNA.
What are hydrogen bonds?
This layer is what contains the DNA when performing the wash step during an organic extraction.
What is the aqueous layer?
These features are what analysts look for when identifying a sperm cell under a microscope slide that has been treated with a Christmas Tree stain.
What is a color gradience, a raindrop shape, and a switch between the light and dark areas from bright field to phase contrast?
These are the three phases that occur, in chronological order, when reviewing a qPCR amplification curve.
What is the lag phase, the exponential phase, and the plateau phase?
When DNA is stored in something highly acidic, it leads to this effect.
What is depurination?
This bond pair requires a higher melting point to denature a DNA strand because they have a triple hydrogen bond.
What are GC bonds?
These are the four steps, in order, to follow when performing a Silica based extraction.
What is lyse, bind, wash, and elute?
These four steps, when listed in order, are required before extracting DNA from a bone sample.
What is clean the area, sample (double what you plan on extracting if enough evidence), pulverize bone in freezer mill, then demineralize in a DMB?
A TaqMan probe does this job during RT-qPCR.
What is place a quencher and signal that is released once a Taq polymerase hydrologies it, allowing the primer to extend the complimentary strand
This type of protein catalyzes the break down of the sugar-phosphate backbone of DNA.
What are DNAses?
Due to this structural combination DNA has a negative charge.
What is the sugar-phosphate backbone?
These three conditions are required for DNA to bind to a silica coated surface during a DNA extraction.
What are high amounts of alcohol, high amounts of salt, and high amounts of chaotropic agents?
The difference between absorbed and emitted wavelengths.
What is the Stokes Shift?
Because of this component a TaqMan Probe does not fluoresce when the probe is intact.
The quencher.
This effect happens to dsDNA when it is exposed to high temperatures.
What is denaturation?
When dsDNA is packaged into a histone, it forms this complex.
What is a nucleosome?
Dithiothreitol (DTT) is used in extraction to break these types of bonds in biological materials like keratin and sperm cells.
What are disulfide bonds?
This non-qPCR quantitation method does not require standards.
What is Spectrophotometry?
UV radiation causes this effect to happen in dsDNA.
What is pyrimidine dimerization?