Blood Typing Lab

Name_____________________________________ Block__________________ Date_____________________ Forensics Mystery riptide Typing Lab Scenario Police ar c all(prenominal)ed to a ho hold where they discover a body near the back door. there is a fresh pool of transmission line by the victims head. Officers disbelief the neighbors and learn that a pipe fitter and an linesman made assistance calls to the house honour fit hours before. They were able to trace both. They recover a shirt with a sliminess stains from the service forefront of the plumber and rags with similar dark stains from electricians van.Your forensics lab receives the spargon-time activity items to study stress 1 varnished textile from plumbers van pattern 2 Stained cloth from the electricians van adjudicate 3 family collected from infra the victims head essay Background The phenolphthalein interrogatory is a super sensitive, being capable of detecting slant spots practically invisible to the eye. In an actual criminal case, a cocksure phenolphthalein essay would be followed by tests to dress the species that produced the kindred and if these tests indicate the familyline is human, by tests to determine ABO, Rh and other origin groups.There is no point in pursue type and species identification procedures if the phenolphthalein test is negative. The phenolphthalein test is not absolutely specific for inception because most plants and some animal mobile phones give notice also cause a supportive reaction. Discussion Questions 1. Does a compulsive phenolphthalein test prove that a stain is caused by blood? 2. Does a positive phenolphthalein test prove that a stain is caused by human blood? map 1 1. Test the shirt and rags to determine if the stains argon caused by blood. 2. Place a degrade of phenolphthalein/peroxide solution on each stain. 3.Observe if a food color change occurs. A purple-violet color reaction indicates that blood (heme) is reconcile (positive reac tion). Absence of this reaction indicates that blood is not impersonate. 4. enroll your results Color reaction for attempt 1_________________________ Color reaction for Sample 2_________________________ Based on the results of this test, which person, the plumber or the electrician becomes your prime distrust? ____________________________________________________________________________ subjoinitional Information When confronted, your chief shadowy claims to arrest a nosebleed, thus report for the blood stain.Investigators have now been able to recover a blood sampling (Sample 4 ) from the suspects van. It is equal for blood typing. You ask and receive a blood prototype from the suspect (Sample 5). prompt to Procedure 2. Test Background Blood groups are created by molecules present on the surface of red blood cells. The parry shows the four ABO pheno founts (blood groups) present in the human population. When red blood cells carrying one or both antigens are exposed to th e corresponding antibodies, they agglutinate that is, bunch together.People usually have antibodies against those red cell antigens that they lack. The ABO Blood bases Blood Group Red Cell Antigen (Protein on blood cell) Serum Antibody (Produced by Body) A A Anti-B B B Anti-A AB A and B neither O Neither Anti -A and Anti -B Discussion Questions 1. How do you determine a persons blood type? 2. Can a persons blood type prove or disprove that he/she committed a crime? How? Procedure 2 1. Add a drop down of synthetic anti-A (blue) to the fountainhead labeled A. sub cap. . Always replace the cap on the vial before opening the abutting vial to prevent cross contamination. . Add a drop of synthetic anti-B (yellow) to the tumefy labeled B. Replace cap. 3. Add a drop of synthetic anti-Rh serum (clear) to the salutary labeled Rh. Replace cap. 4. Using the eye dropper vial, place a drop of Sample 3 (the victims blood) in each well of the blood typing slide. DO NOT TOUCH THE head 5. Re place the cap on the dropper vial. 6. Using a different color mixing roast for each well (blue for anti-A, yellow for anti-B &038 white for anti Rh), gently stir the synthetic blood and anti-serum drops for 30 seconds.Remember to discard each mixing stick after a single use to avoid cross contamination. 7. WAIT 60 Seconds. 8. Carefully examine the thin films of fluid mixture left behind. If the film frame uniform in appearance, there is no agglultination (no clumps, negative reaction). If the film as clumps, agglutinating activity has occurred (positive reaction) 9. Determine blood type of the sample using the data table below. reception yes or no as to whether agglutination occurred in each sample. A positive agglutination reaction indicates blood type. 10. enrol the results for each blood sample in the data table.Data Table Sample 3 Sample 4 Sample 5 Anti-A Anti-B Rh Blood type 11. thence repeat steps 1-9 for Samples 4 and 5. Record each results on table. 12. T horoughly launder the blood typing slides and return all materials. Conclusion Based on your results, did the blood collected from the suspects van come from the suspect? ____________________________________________________ Could this blood have come from the victim? ____________________________ What can you purpose from your results? (Remember to cite your data). __________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ _________________________________________ __________________________________________ ______________________________________________________________________________________________________________________________________________________________________