Lecture 8 Flashcards
What is a way to detect any electrophoretic changes under the course of the run?
By interspacing the allelic ladders between samples; either btwn lanes, on a gel, or injections on a CE machine.
What is a panel? What does it do?
The list of the basic properties of an STR complex. It is needed to correctly call each allele.
It describes the allelic ladder, these are the alleles, these are their sizes, and their colors.
How is STR pronounced
star
Whta does CODIS stand for
Combined DNA index system
What is CODIS system?
they are the standard set of loci entered into the USA convicted offender database
Why do people use non-CODIS STRS in kits?
For exclusion purposes, because it could be something common such as eye color, but if you are dealing with really close relatives who are sharing many alleles, you can exclude someone
What are things to maintain instrument?
spectral and spatial calibration, as well as checking buffer, capillary array, and polymer are good
What are the two main aspects of running an analysis?
Defining the run module and the plate record
(Other than loading or unloading the plate assembly)
What is the run module?
instrument protocol, basic instructions for the machine
What is plate record?
Naming all your samples on the software
What sources of data are used to complete the genotype?
- amplified sample alleles
- external size standard
- internal size standard
What two aspects do you need in order to get a result from a gel?
Sample and ladder
(just to get results)
What do the “bins” (the shaded stripes on electropherogram) do?
Show you the location for the common alleles
What does OL (OLA) stand for?
Off ladder allele; when the software cant call an allele bc it doesn’t fall into a bin
How do you manually determine an allele that was OL?
there are four base pairs between ea allele, so in the middle is .2 and on either side is .1 or .3
What is Y indel or Y in graph
Another method of sex determination
Regression line is used to
(Southern regression line or local)
Translate time into base pairs to estimate size of a sample allele
What is a Global Southern Regression line
- x is time, y is size
- based on all size standard data
- global southern uses all points
- More accurate
What is a local southern regression line
- only uses the four points closest to sample allele
- gives whole numbers
- default in the software
How are DNA fragment peaks sized?
Using the sizing curve prod from the points on the internal size standard
