Important Notes:
1.We have to bring small containers or reaction plates for mixing, something for scooping, pH paper, a magnet, a hand lens, microscope slides and cover slips, forceps or tweezers, writing instruments, a pencil (for chromatograms), and paper towels.
2. We don't have to bring all of these, but it'd make stuf a whole lot easier
3. If anything besides those is found on us, we lose points.
4.Each team membermay bring one 8.5x11 sheet of paper with hand written notes (no photocopies), on either or both sides. The note sheet may be laminated or otherwise protected in a clear covering.
5.Students must wear pants or skirts that cover the legs to the ankles.Students must bring and wear a lab coat or apron that reaches below the knees. Students must wear closed toed shoes and OSHA-approved non-vented or indirect vented chemical splash goggles. Students who fail to meet any of the above safety requirements will not be allowed to participate. Tasting or touching the chemicals will result in disqualification. Gloves are optional. Students who unsafely remove their safety clothing/glasses will be disqualified from the event. Anyone observed handling any of the material or equipment in a hazardous manner will be disqualified.
6. Basically, it's like having Vontroba as your teacher.
7.YOU WILL BE ASKED TO WRITE A SUMMARY. INCLUDING WHO DID IT, WHO DIDN'T, AND THE ORDER IN WHICH EVERYTHING HAPPENED!!!!!!!!!
8. FINALLY!!!! Just read the thing.
KNOW WHAT TO STUDY!!
PART ONE: FINGERPRINTING:
--3 types of fingerprints:
Whorl, Loop, and two types of Arch.
-- the two dif kinds of arhes are Tented arch and Plain arch.
Make sure you know the differences between loops and arches. they're kind of hard to see the difference
Pop Quiz. Look at your own fingerprints and identify each of your fingerprints.
PART TWO: Know the Table of Elements.
PART THREE: DENSITY!!!
Don't forget, density is a very important part for figuring out different elements. Let's review.
1. Density is how densely packed together molecules in matter are.
2. Density can be measured in g/cm³, g/cc, or g/mL. (can be kilograms or liters. make sure they kinda match)
3. Density is a characteristic of matter, like it's freezing or boiling point. SO, each element has it's own and specific density.
4. To find density, take the mass of the object, and it's volume.
5. To find the mass of an object, put it onto an electronic balance. If it's a liquid, zero the scale with an empty graduated cylinder on it, fill the graduated cylinder with the liquid, and mass it out. If it's a gas, mass out the container with a nozzle and washer, pump out as much of the gas as possible, weigh the bottle with the nozzle and washer, and find the difference of the masses.
6. To find the volume of an object, you can use the volume formulas for the specific object, or the water displacement method.
7. Remember, always check your work.
THE ONE DENSITY YOU SHOULD KNOW!!!!
Water 1 g/mL
Pop Quiz. Identify the density of Vegetable Oil WITHOUT using the internet. If you dont have any vegetable oil, try the density of Aluminum, a Quarter, or of air.
PART 4: HAIR ANALYSIS
Basically, you're going to look at hairs underneath a microscope. Here's what you're going to have to do.
1. Since we're not professional forensic scientists, we're not going to use super-advanced equipment, to tell you the truth, we're only going to analyze the hair through a microscope.
2. We're going to have to be able to identify if the hair is a human, dog, or cat hair.
3. We need to identify the basic shape, curliness, and size of the hair.
4. WE NEED to know the color of the hair and know if it's died or not.
WHAT YOU NEED TO KNOW!!!
1. Some hairs are flat and others are round.
2. Some hairs are fine (smooth) and others are course (rough)
3. Round hairs are usually straight.
4. Flat hairs are usually tightly twisted or curly under a microscope
5. Cat hairs are usually finer than dog or human hairs.
6. Dog hairs can be either VERY course and really straight as the outercoatORVERY fine (it can be very curly too) as the undercoat.
7. For naturally-colored hair, dark hair is the thickest, followed by blonde hair, and red hair is the thinnest.
8. Basically, the darker the hair is, the thicker it is...with the exception of red hair, which is the thinnest.
But what if the hair is dyed???????
Well......
1. Hair is made up of two basic layers.
2. The inner layer is the one that holds the pigment
3. Melanin is basically the most common pigment in hair, usually determining the color of the hair.
4. It kind of works like the thick and thin thing, the darker the hair is, the more melanin there is. (except this time, red hair is NOT an exception)
5. If hair is white, there are bubbles in the inner layer.
EEEEEEEEEEWWWWWWWWWWWWW!!!!!!!!
So what does this all mean?
Basically, even if the hair is dyed, you can still tell the REAL color of the hair by looking at the inner layer.
ART 5: FIBER ANALYSIS!!!!! because it's similar to hair analysis
1. It's basically like hair analysis. Only with fibers.
2. We have to identify the difference between vegetable, animal, and man-made fibers.
3. Animal fibers are silk and wool. Stuff from animals.
4. Vegetable fibers are stuff like cotton and linen. Stuff from vegetables.
5. Man-made fibers are stuff like nylon, Dacron, polyester, orlon, acretate, acryllic. Stuff made by scary men in laboratories.
HOW TO TELL THE STUFF APART
1. This is obvious, LOOK AT IT!!!! You can tell a lot of stuff apart using a magnifying glass. Smoother fibers are more likely to be man-made. Most naturally made things are short fibers twisted together in some weird way. The loose ends usually have stuff sticking out like fuzz.
2. To tell you the truth though, most clothes are a mixture of man-made and natural fabrics. So...you're probably thinking...WE'RE SCREWED!!!!
3. So what do we do? BURN TEST!!!! Take the fiber, and put it really close to a flame, make sure they don't touch. A man-made fiber will melt faster than an organic one.
4. What else can we do? BLEACH. Basically, take the fiber, and dip it into a bleach. The animal fibers will melt away. Weird, huh?
5. There's one more thing we can do. DYE. Only some fibers absorb some dies. Just get a chart or something.
Hey what if I don't have the time or equipment to do this?
Well...you can memorize all of this!
*Note* These are all relatively common fibers.
Wool:Wool is the most commonanimalfiber. Under a microscope, wool looks like a really long cylinder with scales on it (eew). The fibers are also usually curly and springy.
Silk:Silk is another animal fiber. It's basically the stuff that makes the cacoon of a worm!!! Under a microscope, silk looks like a really thin, long, and smooth cylinder.
Cotton:If you didn't know, cotton is a very popular fiber. What you probably didn't know is that most cotton is treated or mercersized. Basically, they stretch the threads and dump it in cold sodium hydroxide to make the threads smooth and lustrous.
Linen:This stuff comes from the flax plant. Linen is usually smooth, long, and lustrous. Under a microscope, linen has jointed cells and split, tapered ends. REMEMBER!!!!! Linen is usually used to make tablecloths, napkins, handkerchiefs, summer clothing, and blouses. So, if you know the fiber is from, say, a winter coat, don't be an idiot and say it's linen.
Man-Made Fibers:Man-made fibers usually look kinda similar, so it's hard to tell them apart. Most of these fibers resemble silk, and are thin, long, and smooth BUT they're a lot thicker and consistent then silk.
Here's a cool comparison chart.
Most natural fibres such as wool, cotton, and linen, have
distinctive appearances that can be detected under the microscope.
Wool, for example, being an animal hair, has a pattern of surface
scales (although wool that is re-used may have lost there surface
scales in the processing). Silk and most synthetic fibres, which are
produced by the drawing out and solidifying of a liquid, have
smooth surfaces. This characteristics makes them difficult to
distinguish one from another merely by looking at them through
the microscope in normal light.
PART 6: CHROMATOGRAPHY!!!!!!!! What sounds confusing, but is really easy.
Chromatography: a greek term meaning "written in color" that is used to seperate substances' various colors
So what do we do?
1. Get a piece of filter paper (coffee filters work well). Filter paper can be either wide or long. Wide is useful for testting many substances, while long is useful for testing some substances.
2. Put a small amount of the substance about 1.5 cm from the edge of the filter paper.
3. Dip the paper into a liquid that will dissolve the substances that make up the color, but make sure the water level is never above or at that of the dot.
4. Wait
5. Take your chromotagram and look at the pretty colors.
So how does it work?
1. Most colored substances like pen ink are a bunch of mixtures of different substances. Since it IS a mixture, it's possible to seperate the different substances.
2. If you didn't know, different things have different combinations of substances to create a certain color. Therefore, each pen, each juice sample, basically, each everything has a different chromotography.
3. When the filter paper is dipped into the liquid, the liquid travels up the paper.
4. When the liquid reaches the color, it dissolves them.
5. The liquid then carries the color with it as it travels upward
6. Each color is made out of different molecules. The molecules have different sizes, different weights, and different dissolving properties.
7. Due to these properties, each color will travel up the paper at different rates, thus separating the colors and leaving a special chromatogram
Here's a picture of a successful chromatogram:
HOW TO DO JUICE CHROMATOGRAPHIES!!!!!!
1. Take your filter paper.
2. Take a toothpick, dip it in the juice, and make a small dot on the filter paper, about 1.5 cm from the edge of the paper
3. Put the filter paper in water, without having the liquid touch the dot
4. Wait 15-20 seconds
5. Repeat 2-4, only place the juice sample in the same spot, and do it three more times (unless you are limited on time, then do it twice)
6. Look at your chromatogram
See, this is easy.
POP QUIZ!!!!! Have someone do a chromatogram of a random pen for you out of five. MAKE SURE YOU DON'T KNOW IT!!!!! After they're done, take chromatograms of each pen, and figure out which one you're friend/parent chose.
POP POP QUIZ!!!!! You know to usually use water as your liquid, but what do you use if water doesn't work????
PART 7: TRACKS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What's going to happen is...
1. You're going to look at tire, bike, or shoe treads.
2. Analyze each and determine which track matches what thing...(if that makes sense)
OR
3. Determine which direction the person was going
4. Finally, if it's a shoeprint, be able to identify if the person was walking or running.
TIRES, BIKES, AND SHOES
1. REMEMBER, the pictures or samples that they give you does not necessarily have to be the same size as the picture of the sample found at the crime scene. It could've been blown-up or shrunken-down. You never know. So, don't rely on size to figure things out.
2. The picture could've been taken at an angle, so you really want to rely on the tread.
3. SO, RELY ON YOUR TREADS!!!!!!!!!!!!!!!!!!!!
Here are just a few examples of the type of treads you might encounter.
STUFF YOU SHOULD KNOW
1. When someone's running, they gain distance because their legs spread far apart. Therefore, when a person is walking, a person's footprints are usually spaced closer together, maybe around one foot from the back of the heel of the frontmost foot to the tip of the toe of the backmost foot. When a person is running, they're footprints are usually spaced farther apart, usually more than two feet apart (sometimes a little less).
PART 8: DNA!!!!!!!!!!
You are going to be asked to compare DNA chromatograms and electropherograms from stuff found at the crime scene to those found on the suspects.
This is probably the easiest thing out of all of them. LOOK AND COMPARE THE SAMPLE TO EACH OF THEM ON THE SUSPECT!
THAT'S IT!!!!!!
You might also have to compare an electropherogram. Basically, it's a bunch of boxes that you try and match. Easy.
POP QUIZ!!!!!
Who did it???
Crime Scene:
A C A G C A A T G T A G T A C A G A T A A G G T T T A C G A T A T
T G T C G T T A CA T C A T G T C T AT T C C AA A T G C T A T A
Betty:
A C A T A G C G C G C C G A G A T A C A T G A T G C A C A G A T A
T G T A T C G C G C G G C T C T A T G T A C T A C G T G T C T A T
Smitty:
A C A G C A A T G T A G T A C A G A T A A G G T T T A C G A T A T
T G T C G T T A CA T C A T G T C T AT T C C AA A T G C T A T A
PART 9: PLASTICS!!!!!!
There are 6 different types of plastics that you should know about
1. PETE
2. HDPE
3. non-expanded PVC
4. non-expanded LDPE
5. non-expanded PP
6. non-expanded PS
They're going to give you a bunch of chemicals with similar densities to figure each one out.
What they want you to do is tell the difference between each