DNA St. Patricks Day Salute to the Molecule of HeredityFrom Biology 110- UNC 1993 Steve Lee
The molecular structure today Is heredity’s DNAWith nucleotides completely comprised of a sugar and phosphate and base
The bases you see are so keenThey include thymine and adenineCytosine and one more with guanine can store all the info with rungs in between
The sides of the ladder you know,are sugar and phosphate which showthat Franklin was rightdouble helix is tightten base pairs per turn in a row
Adenine and thymine can base pairForming two hydrogen bonds for one stairCytosine and guaninepair with three in betweenand are equal in size when compared
DNA strands are just not the sameOne is coding and one is called lame (anticoding)They are opposite in direction and thisis called antiparallel in name
Complimentary nature of strandslets replication proceed just as plannedwith A paring to Tand G pairing to Cthe fidelity is precise and quite grand
Steps in Forensic DNA typing(Figure 6.1 Rudin and Inman 2001)Evaluation- Is it there?
1. Start with biological sample
2. Screen- blood? Semen? Saliva, human?Extraction- Get and clean DNA3. Open cells Get DNA
4. Methods to get DNA and purify DNA
Quantify- Determine quality and quantity?
5. Quantify- How good and how much did you get?
Type to determine and compare alleles 6. RFLP vs PCR
7. Determine alleles and compare DNA typesOr alleles present in samples and references
Interpretation of Results
Review: DNA is organized inside the cell nucleus and mitochondria
DNA Extraction
After screening tests are performed, a spot of the material containing the biological sample is cut and placed into a tube.
In one type of extraction method (organic), heat and chemicals are added, and protein is removed. Then the pure DNA is recovered by filtration in which the non-DNA material goes through a sieve.(analogous to a collection of your pasta in a colander)
