dan recovery, extraction and quantification Flashcards
what lab conditions are needed
controlled enironment
positive pressure air
disposable clothing
single direction flow
laboratory controls
what is a substrate control
used to monitor levels of dna and levels of contaminants
sample taken from area adjacent to area of interest
discrete sample
solid sample with dna contained
outer exterior can be washed to remove contamination
i.e. teeth or bone
non discrete sample
cannot be washed , e.g. vaginal swab
what negative controls are needed before we extract dna
- substrate control
- environmental control
- method control
what positive controls are needed before we extract dna
- high quality dna of known origin
- used with caution due to cross contamination
what positive controls are needed before we extract dna
- high quality dna of known origin
- used with caution due to cross contamination
what are the stages for dna extraction
- disrupt cell membrane
- denature proteins
- purify dna
what is used to disrupt the cell membrane and how
detergents
separates histones from dna
denatures histones
destroys secondary and tertiary dna structure
what does denature means
disrupts the secondary and tertiary structures of dna, without destroying the peptide bonds between amino acids
what effect does chelex 100 have
protective effect on dna
chelating resin that has a high affinity for metal ions
what is dtt
disulfies –> dithiols
used for extraction dna from sperm cells
what does pcr stand for
polymerase chain reaction
what speeds up degeneration
water (hydrolysis)
microbial activity
endogenous enzymes
what is electrophoresis
movement of a charged particle in an electric field
