DNA testing

1. hydrogen peroxide

 Top right: sample 1, Top middle: sample 2, Top left: sample 3, bottom right: sample 4, Bottom middle: sample 5, Bottom left: sample 6

After adding hydrogen peroxide, samples 4, 5 and 6 bubbled.

Results: 

Sample 1

My prediction: May be blood -> Red 

Observation: No bubbles

Result: Negative 

Sample 2

My prediction: May not be blood -> Orange

Observation: No bubbles

Result: Negative

Sample 3

My prediction: May not be blood -> Pink 

Observation: No bubbles

Result: Negative

Sample 4

My prediction: May be blood -> Red and quite thick

Observation: Bubbles!

Result: Positive

Sample 5

My prediction: May not be blood -> Purple 

Observation: Bubbles!

Result: Positive

Sample 6

My prediction: May not be blood -> bright red with small particles flatting around 

Observation: Bubbles!

Result: Positive

Conclusion: Samples 4, 5 and 6 may contain blood as hydrogen peroxide reacts with blood and bubbles. 

2. Luminol testing

 Spray Luminol on all three samples

 Notice sample 4(one on the left), it glows

Notice that sample 5 also changes colour

 Notice that the colour of all three samples are different

Results: 

Sample 4: Glowed when luminol was applied

Sample 5: Glowed when luminol was applied

Sample 6: Didn't glow

Conclusion: Sample 4 and 5 may be blood as Luminol chemiluminescence can react with a number of substances such as copper or copper-containing alloys, ; and, as a result, producing the typical blue glow

3. Kastle Meyer Reagent 

 Before adding the reagent 

 After adding reagent

Results: 

Sample 4: Changed colour -> pink

Sample 5: No change

Conclusion: Sample 4is blood

DNA extraction

We also extracted DNA from our cheek cells but unfortunately, i didn't take any pictures.