Analysis of blood splatter!

In this lesson, we analysed the blood splatter made on a piece of butcher sheet by Clara's group, comprising of her, Mavis, Zek Min and Cynthia. After analysing, we were supposed to make a video, explaining how the blood splatters were made. Even though we were only supposed to have 25 minutes to complete discussion and video-making, our class took quite a long time of an hour(?).

HERE'S THE VIDEO! enjoy (:



My group members: Audrey, Jia Min, Yuexin and I.

Blood Splatter! Lab Lesson Data

We conducted 2 experiments in that lesson, namely to find out 2 things:
1) To investigate how the diameter of the blood stains vary with the height
2) Investigate how the shape of the blood stains vary with the angle of impact

The photos have already been uploaded in the previous post (:

DATA:

Blood Splatter Practical

This is my iphoto book! :D filled with pictures taken during practical itself (: I know the last few pages aren't filled but i cant seem to delete them because iPhoto doesnt allow me to ):

anyway, ENJOY!

Chromatography and Flames

Chromatography Experiment!

Procedure:
1. Cut rectangular pieces of each digit out of cheque paper, keeping in mind order of digits.
2. Use forceps to transfer each piece into each Microfuge tube.
3. Pour a little ethanol (NOT TOO MUCH) into Microfuge tubes, just enough to cover digits.
4. Gently shake Microfuge tubes.
5. Draw pencil line 2 cm from width of each strip of chromatography paper and label each one (e.g marker ink, digit no. 1)
6. Use capillary tube to transfer ink from each Microfuge tube to the pencil line of each chromatography paper strip.
7. Use the marker (i.e. 1 or 2) to dot on one of the chromatography papers.
6. Fill each boiling tubes with 1ml of distilled water.
7. Dip each chromatography paper into each boiling tube so that the pencil line is a little above the water level. Use wooden peg to hold the paper in place.
8. When the solvent is about to reach the wooden peg, quickly remove the paper from the boiling tubes and mark the solvent fronts.
9. Calculate Rf values and compare.

PICTURES! (:








Flames hands-on!
Copper (II) Nitrate



Barium Nitrate




Sodium Nitrate




Lead (II) Nitrate




Potassium Nitrate



Calcium Chloride





Fascinating pictures of MS TAN conducting some experiments!

FINGERPRINTING!

Order of fingerprinting methods in our FIRST lab practical:
1) Iodine Fuming
2) Ridges and Pores Activity (wood glue)
3) Cyanoacrylate (Superglue) Fuming Method
4) Powder Dusting Method

Iodine Fuming!
Fingerprints can be seen using this method because natural body fats and oils in the larent print temporarily absorb the iodine vapours, resulintg in a change in colour, often from colourless to dark brown. However, this change fades after a while as the iodine that was absorbed eventually dissipated into the atmosphere.

Placing filter paper into the glass jar with iodine fumes:




Close-up:



Product (the one on the left is Audrey's and mine's on the right)



Cyanoacrylate (Superglue) Fuming Method

Superglues typically contain methylcyanocrylate or ethylcyanoacrylate which react with traces of amino acids, fatty acids and proteins in the latent fingerprint and the moisture in the air to produce a visible sticky white substance along the ridges of the fingerprint.



order of fingerprints: audrey's mine michelle ang's and heidi's

Ridges and Pores Activity

A friction or epidermal ridge is a raised porton of the skin on the fingers and toes. Impressions of fingerprints may be left behind on a surface by natural secretions of sweat from glands that are present in friction ridge skin.

When the glue is undried:



The dried version:



Last but not least, the powder dusting method!

Oils and perspiration from the common residue on finers that get transferred when a print is made. When the powder is applied to the suface with the print, it sticks to the oils and brings out the ridge patterns.



its now pasted onto my worksheet!

MY FINGERPRINT DATABASE!