ASCL Possible Interview Questions
ASCL GOALS
1.Complete cases in a timely manner to meet our customer's expectations 2. Improve retention of Forensic Scientists 3. Keep Law Enforcement up to date of laboratory services and capabilities 4. Keep Coroners up to date on Medical Examiner services and capabilities 5. Fund Lowell Satellite Laboratory 6. Develop a plan for a new Forensic Science Facility
Year ASCL formed
1977 by Act 517
Year Crime Lab Board of 8 was formed?
1991
1997
AR State police moved
PCR components
DNA template DNA Polymerase Oligonucleotide Primers Deoxynucleotide triphosphates Buffer system
Lean Six Sigma
Defects Over-Production Waiting Non-Utilized Talent Transportation Inventory Motion Extra-Processing
ASCL Vision
Ensuring a safer Arkansas by providing the Criminal Justice System quality results within thirty days of submission which allows law enforcement the ability to respond quickly and effectively to criminal investigations.
Funded by?
General rev, Special rev. and fed grants
Buffer system
Includes magnesium and potassium to provide the optimal conditions for DNA denaturation and renaturation; also important for polymerase activity, stability and fidelity.
1981
Lab became independent agency; shared building with AR State Police
Please describe the principles behind PCR
PCR involves the primer mediated enzymatic amplification of DNA. PCR is based on using the ability of DNA polymerase to synthesize new strand of DNA complementary to the offered template strand. Primer is needed because DNA polymerase can add a nucleotide only onto a preexisting 3′-OH group to add the first nucleotide. DNA polymerase then elongate its 3 end by adding more nucleotides to generate an extended region of double stranded DNA.
Core Values
Quality Teamwork Safety Clear communication Accountability Professional development
Oligonucleotide Primers
Short pieces of single stranded DNA (often 20-30 base pairs) which are complementary to the 3' ends of the sense and anti-sense strands of the target sequence.
Deoxynucleotide triphosphates
Single units of the bases A, T, G, and C that provide the energy for polymerization and the building blocks for DNA synthesis.
What would you do if you think you might have contaminated a sample?
Stop and analyze the situation; ask superior
ASCL Mission
The Mission of the Arkansas State Crime Laboratory is to provide the highest quality scientific services to the criminal justice community and the State of Arkansas. This is accomplished through a team of skilled and dedicated employees utilized scientific equipment and appropriate validated methodologies. The laboratory strives to provide these services in a timeframe amendable to our customers.
ASCL is led by an executive director who is appointed by who?
appointed by the governor
PCR Steps
denaturation, annealing, elongation
DNA Template
double stranded DNA (dsDNA) of interest
Denaturation
eating the reaction mixture to 94°C for 15-30 seconds. During this, the double stranded DNA is denatured to single strands due to breakage in weak hydrogen bonds.
Please describe to us how you would examine a piece of evidence for the presence of biological materials, such as semen, blood, saliva, urine, and feces. Please describe the process as if you're speaking to a group of middle school students.
ehh
What is Quality Assurance and what should a lab do in order to make sure Quality Assurance is in place?
maintenance of a desired level of quality in a service or product, especially by means of attention to every stage of the process of delivery or production. Meetings and weekly reviews, asking questions, reading
1979
placed in the Department of Public Safetly
What is a presumptive test? Example?
presumptive test is a qualitative analysis that allows to identify, or confirm, the presence of a substance in a sample. These determinations usually occur, after a chemical
Annealing
reaction temperature is rapidly lowered to 54-60°C for 20-40 seconds. This allows the primers to bind (anneal) to their complementary sequence in the template DNA.
What is a confirmatory test? Please give an example of each.
tests required to confirm the analysis.; more expensive too
DNA Polymerase
thermostable Taq polymerase that does not rapidly denature at high temperatures (98°), and can function at a temperature optimum of about 70°C.
Elongation
usually occurs at 72-80°C (most commonly 72°C). In this step, the polymerase enzyme sequentially adds bases to the 3′ each primer, extending the DNA sequence in the 5′ to 3′ direction. Under optimal conditions, DNA polymerase will add about 1,000 bp/minute.
