Quant Analysis
EPG Trouble Shooting
Contamination
Statistics
MISC
100

Define the targets in QT:

-Small

-Large

-Male

-IPC

Small= amp targeting

Large= degredation

Male= YSTR targeting

IPC= checks for inhibitors/the rxn worked.

100

What is ILS? What would happen if ILS isn't added to a tray?

ILS is the internal lane standard that sizes the length of the unknown DNA fragment.

If ILS isn't added, then the data would not be able to size correctly, and may not show up.

100

What's the difference between random and systemic contamination?

Random= one single RB or sample

Systemic= Multiple samples/RBs affected

100

What are the conclusion requirements for a single source profile?

Under 3 alleles= INC

3 alleles= Inclusion

3+ Loci= Exclusion

100

Who is Bode Accredited by?

-ISO 17025

-ANAB

200

What does a high or low Ct mean?

High= reaction worked, DNA is not degraded

Low= degraded sample, or too much DNA template

200

What is the purpose of a ladder?

The ladder provides the allele calls for the unknown peaks. If ladder isn't added properly, the peak will not be called, or will be all OL.

200

What if an RB passes per SOP?

1. Attempt to Source

2. Determine if random or systemic

3. Random= RB passes, case note

4. Systemic= RB fails, reprocess all processed in parallel. No TL for new data, case note

200

What do we use RMP for and why?

Single Source inclusions, because it follows the product rule of independent assortment.

200
What is ST/AT for all amp kits?

GF: 600, 125

PPF: 500, 100

6C: 600, 100

24plex: 600, 100

300

What does it mean when IPC flags? with a large DI? Large DI and no IPC flag?

That the sample is inhibited. The sample is inhibited and degraded. That the sample isn't inhibited but is degraded.

300

What is stutter? What is the N and the -X?

Stutter is caused by an amplification error where the template bulges out and a repeat is either added or not included. 

N=true allele peak

-4= minus one repeat, -4bp behind the true peak

300

What if an RB fails per SOP?

Attempt to source and determine if random or systemic. 

Systemic= RB and associated samples fail. Reprocess

Random= Check quant data

300

What is CPI and why do we use it?

CPI is used for mixture statistics that were not able to be deduced to single source. They are more conservative because they don't use product rule.

300

What is the purpose of Y Markers in STR kits? and Yindel?

-Can be used to determine a male profile if Y is null

-Yindel is a shorter polymorphism that men have either an insertion 1 or deletion 2

400

What if the IPC flags with a quant value?

There's too much template DNA

400

What do you check when deciding to reload/amp/inject?

-Check what went wrong

-amp target, reagent issue, instrument issue

400

What if the RB/Sample quant doesn't indicate contamination?

1. Reload

2. Reamp

3. Reextract

if contamination is gone, then can report data. If not, data fails and scrutinize data to determine if impacted.

400

Which locus are suitable for stats?

SS: all locus with a pair or 2p rule for one allele at a locus

Mix: 3+ all locus over ST, 2 if all alleles are accounted for

400

Define and identify Stochastic Effects

When other alleles/loci are preferably amplified over others resulting in drop out and alleles under ST

500

How to troubleshoot high female profile in SF

-ProK spike

-YSTRs

-try to deduce

500

What's required for a foreign mixture worksheet?

-2 person mix

-body swab

-need a reference sample

500

How to source Contamination

1. Check GMIDX

2. Check BodeMatch if it's a known contaminate

3. If sourced, check steps of coprocessing to determine when it occurred.

500

What are conclusion requirements for a mixture?

Inclusion: 3+ complete alleles

Exclusion: Represented at 3+ loci

INC: Under 3 loci

500

What are the RB passing guidelines

GF/PPF/6C: no more than 1 peak over AT, or up to 3 peaks under AT and one under 250rfu

24plex: no more than 3 peaks under AT