NotEvenWrong
Muse
- Joined
- Jun 14, 2014
- Messages
- 910
Tutorial No. 2
Today's exercise
Apparatus
I want you all to take a small glass of fruit juice and another of tap water.
Method
1. Take a small amount of the fruit juice and mix it 1:1 with the water. Stir. Put aside.
2. Taking a small amount of the water, say a teaspoon, pour it onto a thick absorbent kitchen towel, or cloth. Leave to dry overnight.
3. 24 hours later, take a teaspoonful of the juice and pour it onto the spot where the water had been poured the previous day. Leave to dry.
4. Take a teaspoon of your stirred fruit juice/water from the day before and por onto a separate sheet of kitchen towel. Leave to dry.
5. Next day, compare the two sheets of kitchen towel.
Results
1. The paper with the fruit juice added to the water 24 hours later is much darker and shows as a separate stain to the water (see around the edges).
2. The mixed fruit juice and water remains a paler colour than the fruit juice added later, as above.
Conclusion
Now imagine scenario one represents Knox' DNA/blood left in the sink sometime before the murder. It is possible to differentiate them as two separate stains left at different times. It will reveal two separate incidences of water and blood but n'er the two were mixed.
In scenario two, the diluted blood of the victim and Knox are deposited in the sink and bidet at the same time means the streak is pale pink (as discovered by Giao (_sp?) and Stefanoni and contains a mix of Knox and Mez', which were deposited at the same time and a separation of the two fluids cannot be ascertained.
Knox' DNA/blood mixed in with Mez' DNA/blood and diluted with water was found as a long narrow streak in the sink and again in the bidet and confirmed by DNA tests showing it was:
- of Knox and the victim
- it was a single sample of blood and water mixed together at the same time
- the mixed DNA was of Knox and Kercher
- the mixed sample tested positive for human blood.
Here endeth today's lesson.
Vixen,
Typically, a scientist (of which you are clearly one, as we can see from your intellect), when performing an experiment, will use the same substance in their method of testing as the one they're trying to learn about. For example, they wouldn't use fruit juice as the compound for experimentation when they're trying to study the properties of blood.
Can you think of why that might be? Hint: it has to do with not making up crazy **** in your head and stating it as fact. You know, science.
