00_title=Can you solve the crime? 11_global_nav=DNA Basics 21_global_nav=Crime Scene 30_global_nav=Lab Tell_me_more_button=TELL ME MORE 11_basetext=Everything in your body--blood, skin, heart, bones, even your big toe--is made from cells. Each cell has an identical copy of your DNA (short for deoxyribonucleic acid), which holds a unique code that makes you you. DNA profiling usually starts by collecting skin or blood cells from the crime scene, victim and suspects. 11_boxtext=Even though each cell in your body has the same copy of your DNA code, your cells use different DNA parts, or genes, to do whatever it is your cell needs to do to be a blood cell, a skin cell, or a bone cell. Scientists use skin or blood for DNA profiling because these cells are relatively easy to get from any suspects, and are often the types of cells left behind at a crime scene. 12_basetext=Each cell has a nucleus, or center, where the DNA is. The first step as a DNA Detective is to break open cells with detergent to get the DNA out. 12_boxtext=Scientists can break open cells by putting them in a water-based solution with detergent. The detergent bursts the cell membrane - the layer that holds the cell together. This releases the DNA. 13_basetext=The nucleus contains chromosomes, which are long strands of twisted-up DNA. Only 0.2% of one person’s DNA will be different from another person's. DNA profiling works by studying the small parts of our DNA that are so different. 13_boxtext=Scientists have figured out that some sections of our DNA code, or genome, are a lot more variable (different) than others, depending on the person. DNA profiling works with these so-called hypervariable regions, often full of bits of DNA called loci that contain a lot of the same code repeated over and over. These are called VNTR loci or minisatellites. 14_basetext=A long string of DNA code is made up of molecules, called bases, repeated over and over in different sequences. A chemical called a restriction enzyme can cut the string at specific points in the code, leaving different sized chunks of DNA. 14_boxtext=DNA is made from four bases: adenosine (A), cytosine (C), guanine (G) and thiamine(T). For example, in a hypervariable region, you might have the code CAGCAGCAGCAG (CAG repeated 4 times). In the same part someone else might have CAG repeated seven times, or twenty times. They might have other CAG repeats in different places too. A restriction enzyme will cut these DNA regions into different sizes depending on how many repeats you have. DNA profiling measures the number and size of these DNA chunks. 15_basetext=DNA chunks are separated on an agarose gel and analyzed as the last step in DNA profiling. Since both the DNA and the gel are clear, dye is added to the DNA before its put or loaded in wells on the gel. An electric current runs through the gel, which acts as a filter, to separate the DNA chunks by size. 15_boxtext=Agarose is a gelatin-like substance that lets the DNA flow through it when a current is applied. DNA has a negative charge, electrically speaking, which makes it want to move toward a positive charge. The DNA is separated by size with the largest pieces staying closest to the wells (usually at the "top" of a gel). 16_basetext=Every DNA Detective should know the basics - now that you do, you’re ready to check out the Crime Scene or head to the Lab. 21_basetext=You got the call that they need a DNA detective at the skateboard park to investigate a crime -- the winners trophy is missing! You arrive to find a group of six skateboarders being questioned by the police, two bloodstains on the sidewalk and reports of a missing skateboard and trophy. @@Here’s the story...@@The Big Board skateboard competition had been close, but the trophy was awarded to the winner -- Charlie "The Board" Jones. After the crowds dispersed, Charlie was congratulated by his teammates, showed off his trophy, and had just skated to the other side of the park on his way home when someone came up behind him and knocked him off the skateboard. A brief scuffle ensued, leaving both the victim and the culprit scraped up from the concrete. The culprit took off on the winner’s skateboard with the trophy. @@The police were on the scene immediately and rounded up the skateboarders in the park and narrowed down the possible suspects based on the victim’s story. Charlie could only describe the culprit as having dark hair, wearing baggy jeans and an orange sweatshirt. Unfortunately, all the City Skaters, including the victim, are wearing an orange sweatshirt, and a lot of them have dark hair. They all of course deny accosting their teammate to steal the trophy. 22_instruction=Click Charlie to see his story. charles_bio_button=Read Charlie’s Bio 22_basetext=Part of analyzing the crime scene is interviewing the victim and the suspects. You might need more information that just a match of DNA to find the thief. A good DNA detective should know each person’s story. 22_boxtext=Charlie "The Board" Jones. [4ft. 10in. 13 years old]. He didn’t see the perpetrator of the crime--just a flash of baggy jeans and orange sweatshirt as they both landed on the concrete. They were both pretty scraped up. His win at the competition is a major upset. There was some rivalry with other kids on the City Skaters--Charlie had been practicing and skating well recently, moving up in the unofficial ranks of the team. Some of his teammates weren’t happy that they were beaten out by Charlie. 23_instruction=Click a Suspect for Details 23_boxtext=Find out what the other City Skaters had to say. Is everyone telling the truth? 23_name_1=Crystal "Half Pipe" Martinez 23_bio_1=Crystal "Half Pipe" Martinez. [4ft. 7in. 12 years old]. She has been skating with the City Skaters for two years and has recently come into her own. She trained hard for the competition and was upset that she didn’t win due to a fall in the last round. She swears up and down that she and Charlie are friends and she would never accost him, even if she were jealous about him winning the trophy. 23_name_2=Henri "Wheels" LaCroix 23_bio_2=Henri "Wheels" LaCroix [5ft. 13 years old]. He and Charlie have always been rivals on the team. Wheels was always #1, but got a little cocky this season and stopped practicing as much as he used to. Consequently, this is the third competition in a row that Wheels has lost out to The Board because of a nasty fall, and he’s visibly upset. He’s got a big mouth and often talked trash about his other teammates. He denies having anything to do with the crime. 23_name_3=Pablo "Speed" Martinez 23_bio_3=Pablo "Speed" Martinez [4ft. 10in. 13 years old]. He’s a newcomer to City Skaters. His sister "Half Pipe" talked him into joining. The Board took him under his wing and has been helping Speed hone his tricks. Speed was running a close second in the competition until he mistimed a jump and fell, scraping his knee pretty badly. He insists he and Charlie are friends and he would never do anything to mess that up. 23_name_4=Anya "Trippy" Tripplehauer 23_bio_4=Anya "Trippy" Tripplehauer [5ft. 1in. 12 years old]. The Board is her ex-boyfriend, yet she claims that they’re still friends and skating buddies. She admittedly isn’t the most talented skater on the team, but loves skateboarding and wishes she could skate as well as The Board and Wheels. She also took a digger in one of her practice runs before the competition and scraped up her elbows. 23_name_5=Sue "Air" Jordan 23_bio_5=Sue "Air" Jordan [5ft. 3 in. 12 years old]. She won the competition last year, and was doing well this year until she fell during her last run. She was upset that she messed up a trick she’d done a thousand times and was seen having a temper tantrum as The Board was awarded his trophy. She claims she wouldn’t want a trophy she didn’t win. 24_basetext=As DNA Detective, you’ll need to:@1. Choose what samples to test from the crime scene and suspects.@2. Process and analyze the DNA evidence in the lab.@3. I.D. the thief. 30_1_label=Tubes to collect samples 30_2_label=Chemicals to process DNA 30_3_label=Pipettor to add chemicals to process 30_4_label=Gel Tray 30_1_text=Each sample goes in its own tube for processing. 30_2_text=Detergent, a restriction enzyme, and dye are used in DNA profiling experiments. 30_3_text=A pipettor is used to add small amounts of chemicals to the samples. 30_4_text=DNA samples are "run" on an agarose gel. 30_21_label=Enzyme 30_22_label=Detergent 30_23_label=Dye 30_2_label=Chemicals to process DNA 30_2_label=Chemicals to process DNA 31_basetext=What samples from the crime scene will you test? Check the boxes and click Collect. 31_label_a=Crime Scene A 31_label_b=Crime Scene B 31_label_v=The Victim 31_boxtext=DNA profiling relies on matching samples taken from the crime scene to the people involved. One of the blood samples should match the victim, Charlie "The Board" Jones. The other should match the thief. 31_collect=Collect Samples 31_0_boxtext=DNA profiling won't work unless you have samples from the crime scene to base your comparisons on. Choose the samples you want to test and click Collect. 31_1_boxtext=Just one sample isn't enough for accurate DNA profiling. One blood sample on the scene is from the victim, but we don’t know which one was his and which one was the thief's. What other samples should you test? 31_2_boxtext=You're on the right track, but you need all three samples to get meaningful results when you analyze the evidence. 31_3_boxtext=A good DNA Detective knows that you need both crime scene samples and one from the victim to process in the lab. We know from the crime scene report that Charlie left one of the blood samples, but we don't know which one unless both sample A and sample B are compared to his DNA. The sample that doesn't match Charlie should match one of the suspects. Click "Next" to collect samples from your suspects. 32_basetext=Which suspects do you want to test? Choose the boxes and click Collect. 32_boxtext=Your job is to find out who left the second blood sample at the crime scene. According to the report all suspects claim they fell during the day of the competition, which explains why they have scrapes and scratches. What we don’t know is which one got hurt committing the crime. 32_x_boxtext=Now that you have your suspect samples, you’re ready to prepare the DNA in the lab. Click "Next" to proceed to the lab. 32_0_boxtext=You must select at least one suspect sample to continue. 32_label_1="Halfpipe" 32_label_2="Wheels" 32_label_3="Speed" 32_label_4="Trippy" 32_label_5="Air" 33_basetext=The first step is to break open the cells in each tube. Click the chemical you want to use. 33_boxtext= 33_label_1=Enzyme 33_label_2=Detergent 33_label_3=Dye 330_1_boxtext=Good choice. The detergent actually bursts open the cells so the DNA can be separated from the rest of the cell. 330_0_boxtext=You'll need that chemical in another step. The detergent will burst open the cells so the DNA can be separated from the rest of the cell. 33a_basetext=Choose the chemical that will cut the DNA into different sized chunks. 33a_1_boxtext=You're right -- restriction enzymes cut DNA strands at specific places. You now have a bunch of differently-sized DNA pieces in each tube (some are small, some are larger depending on how many minisatellites are found in each chunk). 33a_0_boxtext=This chemical is used in another step. Restriction enzymes cut the strands of DNA. 33b_basetext=Add the chemical you need to see the DNA before you load your gel. 33b_1_boxtext=Right. Since both the DNA and the gel are clear, dye is added to the DNA solution to help you see what you’re doing. Each sample is loaded into wells at the top of the gel. 33b_0_boxtext=This chemical was already used in another step. Adding dye to the tubes will help you see the DNA solution as you load the gel. 33c_basetext=Click "Next" to proceed to the next step and load your gel tray. 34_boxtext= 34_0_boxtext=Almost -- remember opposite charges attract. Since DNA is negatively charged, it will move toward the positive charge. If you put the positive electrode at the well end of the gel, all the DNA will run right off the end before you get a chance to analyze it! 34_1_boxtext=Good choice. DNA is negatively charged, so it wants to move toward a positive charge. Putting the positive electrode at the bottom of the gel lets the DNA get separated with the larger pieces close to the wells and the smaller pieces closer to the bottom. 35_instructions= The DNA is ready to be separated on the gel. Choose which end of the gel should have the negative electrode then apply current. 34_apply=Apply Current 35_basetext=Compare the DNA patterns and click the box to choose a suspect. You're looking for a match to the other blood sample recovered from the crime scene. (Hint: you can drag the sample a and b). 35_boxtext= 35_0_boxtext=Great detective work! Crime scene sample A is a match to the victim. This means Crime scene sample B must be compared to the suspects -- your keen eye made the match! 35_1_boxtext=Not quite! Take a closer look at the DNA patterns and choose a better match. 35_2_boxtext=Good try, but still not the best match. It looks like Crime scene sample A matches the victim. Which suspect matches Crime scene sample B? 35_3_boxtext=Almost, but a better match of the DNA patterns is the highlighted sample (if you don't see a highlighted sample you should go back and consider other suspects). 35_4_boxtext=Hmmm... Crime scene sample A matches the victim. Did you test the right suspects? You might want to go back to the suspect line up and choose again. 36_basetext=You’ve made the match, but you’re still not done! DNA profiling also relies on the probability of how many people in a population share the same DNA pattern.@@Take a simple DNA pattern with three fragments. Say fragment 1 is found in one in every ten people, fragment 2 is found in one in every seven people, and fragment 3 is found in one in every 234 people. Suspect 2 and the thief share all three fragments. The combined probability of two people sharing all three by chance is one in every 10 x 7 x 234 people. So there is a 1 in 16,380 chance that suspect 2 shares the genetic pattern with the thief by chance.@@Think about an average city of 500,000 people. It’s likely that there are about 30 people in the city that share the genetic pattern with the thief. Do you still want to convict suspect 2 on the basis of genetic evidence alone? It’s important to consider all the evidence in a crime before you convict someone. Does the seriousness of the crime make a difference in your decision? 36_finish_label=What really happened? 37_restart_label=Restart 37_2_boxtext=Great DNA Detective work! When he was told his DNA matched the sample from the crime scene, Henri "Wheels" LaCroix admitted to lying when he was first questioned about what happened. He said he was jealous of Charlie and stole the trophy. Henri did return the skateboard and trophy, but will be skating with a different team from now on. 37_4_boxtext=Congratulations on solving the crime! The DNA evidence led Anya "Trippy" Trippelhauer to confess that she was having a hard time since Charlie broke up with her and wanted to get back at him. She apologized and returned the skateboard and trophy. Charlie had no idea she liked him so much, and is considering getting back together with her. 37_5_boxtext=Nice work! Your DNA profiling identified Sue "Air" Jordan as the thief. She later admitted to being a sore loser and stealing the trophy and skateboard in a fit of rage. Sue returned the stolen property and promised to enroll in an anger management course.