FRSC 460 DNA analysis Midterm

Who is generally considered the father of forensic DNA typing?

Alec Jeffereys

How many chromosomes are present in DIPLOID human cell?

46

The inventor of PCR is:

Kary Mullis

What type of bag should be used for collecting DNA at crime scenes?

Paper

Where can DNA be found?

White blood cells

The Phadebas test:

identifies amylase

Which component of feces does the Edelmann's test identity?

Urobilinogen

The DNA backbone is composed of:

Phosphates and sugars

Why are SDS and proteinase K added to DNA samples prior to extraction?

To break open cell walls AND break down the proteins.

Which of the following is used to describe an extraction method used to separate sperm cells from epithelial cells?

Differential

Confirmatory tests for bodily fluids can be easily done in the field. (True/False)

False

The Chelex extraction procedure requires multiple tube transfers. (True/False)

False

Which describes the ability of a test to detect minute amounts of a substance?

Sensitivity

Which of the following describes the ability of a test to detect the bodily fluid you are testing?

Specificity

How many genetic loci do the new STR kits target in order to comply with the new CODIS core loci?

20+ loci and a sex-determining marker

What is the purpose of DNA quantitation?

- To provide information about the quality of the DNA extracted

- To provide information about how much human DNA was extracted

- Gives a clue as to how to proceed with the sample downstream

When an electric field is applied during electrophoresis DNA will migrate towards:

The positive electrode (anode)

What piece of equipment is used to amplify DNA?

Thermal cycler

The size range for an STR repeat is:

2-6 bp

What is the dominant method utilized by the forensic DNA community for detecting DNA molecules?

Fluorescent detection

In addition to the template DNA, the key components of a PCR reaction are:

dNTPs, Taq Polymerase, primer pairs, buffer

In RT-PCR, the more cycles it takes to cross the cycle threshold (CT), the more DNA is present in the sample. (True/False)

False

Pre- and post-PCR sample processing can be done in the same area. (True/False)

False

During the capillary electrophoresis, the detection step occurs prior to separation (True/False)

False

Fluorescence occurs when a molecule absorbs light of a longer wavelength and emits light of a shorter wavelength. (True/False)

False

In a PCR reaction, the annealing temperature is higher than the denaturing temperature. (True/False)

False

Electrophoresis is the process used to separate molecules based on _________________ and ________________.

charge and size

The three PCR steps in order are:

Denature, anneal, extend.

If the human DNA signal does not cross the threshold but the IPC signal does cross, what conclusions can be made:

There is no human DNA detected.

The CT for the 50 ng/uL is 10 and the 40 ng/uL std CT is 11. How much DNA is in a sample with a CT of 10.5?

45 ng/uL

The higher the voltage, the lower the current. (True/False)

False

What is the purpose of a spatial calibration?

To indicate the position of fluorescence from each capillary on the CCD.

A primer is:

- A short, chemically synthesized DNA sequence

- A DNA sequence which binds to the regions flanking to the STR of Interest

- A DNA sequence which contains a fluorescently labeled dye

If you had 1 non-nucleotide linker to prevent overlapping size ranges of PCR products, how many bp is the shift?

2.5 bp

What purpose does the polymer serve in capillary electrophoresis?

A mechanism to separate alleles in the sample.

During an organic extraction, the DNA transfers to the organic phase during the phenol/chloroform step. (True/False)

False

Which one is reduced and colorless?

Phenolphthalin

What is the proper order of the phases of qPCR?

Exponential, linear, plateau

During which phase of qPCR are the cycle threshold measurements taken?

Exponential

In the TaqMan 5' Nuclease assay, the quencher dye will fluoresce when it is no longer close to the reporter dye. (True/False)

False.