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2010-04-28 08:31:52
BU forensics

Questions for labs
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  1. Why is it important to record the results from the o-tolidine test within 10-15 seconds
    To redue the chance of recording a false positive: Natural oxidation from the air can cause the colored form to appear after longer time intervals even in the absence of blood
  2. What is known to cause a premature positive result with tetramethylbenzidine
  3. T/F unlike LMG, TMB is a conclusive test
  4. The color change for catalytic color test for blood should occur
    After the addition of the oxidizer
  5. T/F Increasing the number of steps in a catalytic color test can increase specificity
  6. Is the Kasle-Meyer test qualitiative, quantitative or both?
    It is only qualitative
  7. When can a catalytic color test yeild a positive result for hemoglobin with saliva?
    When there are trace amounts of blood in the saliva
  8. Horseradish will give a false positive for blood after?
    The addition of the oxidizer
  9. Most of the forensic literature points to________ as the most specific presumptive test for blood
    Leucomalachite green
  10. Animal blood with give a ____ result with O-tolidine

    not species specific
  11. Microcrystalline test for blood confirm the presence of:
    Heme derivatives
  12. Hemochromagencrystals are________ in appearance.
    bright red and feathery
  13. A reason for a negative Teichman test of a known blood stain may be
    the sample may have been over heated
  14. Which microcrystalline test does not require hight temperatures for crystallization to occur?
  15. Hematin crystal formation in a bloodstain can be induced by using salt____ and ____ under _____conditions


  16. The specificity of antigens and antibodies is based on their:
  17. Where on the RBC are antigens located?
    on the membrane of the red blood cell
  18. A person's ABO blood type refers to the ____ present
  19. Type O blood contains what antibodies?
    Anti-A and Anti-b
  20. Which presumptive test for blood is considered not to be carcinogenic?
  21. Kastle Meyer test is also known as?
    Phenolphthalein test
  22. McPhail's reagent is also known as
    Leucomalachite green
  23. A leuco dye in the _____ form is colorless
  24. A 1:2 serial dilution is started by using 1mL of blood and adding ____ of water
  25. For blood samples used for species testing the blood should be diluted with buffer until a _____ color is observed

    A sample too strong may overwhelm the antibody
  26. Cross reactivity usually occurs with:
    Closely related species
  27. In the Oucherlony diffusion method, more than one band may form if:
    different components of the extract have different diffusion coefficients
  28. In a positive chromatographic immunoassay, the Test area "captures" _______ that formed in the sample well and causes a visible reaction.
    mobile antigen-antibody complexes
  29. antigen; high dose hook
  30. Acid phosphatatse catalyzes the breakdown of _____ which then reacts with a _____ to produce a colored compound
    alpha-naphthyl phosphate ; colorless azo dye

  31. Question 8 answers
    5 minutes
  32. A weak or slow reaction using the AP Spot Test means that the stain:
    Could be vaginal fluid
  33. The presence of _____ can inhibit the fluorescing of semen stains while using ALS
  34. What is the best order to process a possible semen stain?
    • Visual exam
    • AP testing
    • PSA testing
  35. What color do nucli stain with H&E?
  36. SVSA
  37. 1:1 million dilution
  38. What color do sperm heads stain with Christmas tree?
  39. What are common things mistaken for sperm heads?
    bacteria, e cell nucli and yeast
  40. Amylase is an enzyme that digests:
  41. How do you differentiate between AMY-1 and AMY-2?
    gel electrophoresis
  42. The RSID immunochromatographic test for saliva is sensitive to:
    0.001mL of saliva
  43. T/F The starch-iodine test for amylase is semi-quant
  44. Which is more specific SALIgAE or Phadebas tube test?
  45. Which test for saliva has an unknown mechanism?
  46. Urine is yellow due to:
  47. Normal healthy males urine is a poor source of:
    cellular materials
  48. Iodine solution or PAS stain can be used to detect:
    the presence of glycogentated e-cells
  49. Glycogentated e-cells stain:
  50. Normal adults produce_____ of urine a day
    .75-2 liters
  51. If a slide constains more that _____% glycogenated e-cells it is most likely a vaginal sample
  52. What does DMAC react with?
  53. Swabs collected from a victim of a vaginal sexual assault approximately 48 hours after the assault will _____ contain semen evidence
  54. 5 to 6 hours
  55. Teichman reagent consists of:
    glacial acetic acid and a halide
  56. The teichmann reagent converts_______ to ______
    Hemoglobin to hemin (hematin)
  57. The Takayama test uses _____ and ____
    pyridine and sugar
  58. The Takayama test induces the formation of ______
  59. Hemochromogen is fromed when ______ from hemoglobin reacts with pyridine
    ferrous iron
  60. What are the reagents used for the presumptive testing of blood?
    • Phenolphpthalein
    • Tetramethylbenzidine
    • Leucomalachite green
    • orthotolidine
  61. The Ouchterlony method relies on the radial double diffusion of:
    Ab and Ag
  62. Immunoprecipitate are visible where:
    Ab-Ag complexes are formed
  63. Azo dyes are:
    • chemcial compounds with a nitrogen functional group
    • usually stable
    • have vivid colors
  64. Reporting a positive result for saliva (general)
    Analysis of ___ gave chemical indications for the presence of amylase, a component of saliva
  65. Negative Saliva result
    No amylase activity was observed/ Amylase, a constituent of saliva, was not detected on____
  66. -Amylase diffusion quant. positive results for amylase equal/larger to 1:100 dilution

    -between 1:100-1:500 dilution

    -less than 1:500
    Elevated levels of amylase were detected on____, which indicates presence of saliva

    Amylase was dectected on ____, Amylase at this level has been observed in saliva as well as other biological fluids

    Low levels of amylase were detected on____, Amylase activity at this level is inconclusive for the presence of saliva
  67. Positive AP
    Analysis or ___gave presumptive chemical indications for the presence of acid phosphatase, a component of semen
  68. Positive Microscopic ID of semen
    Microscopic examination of ____demonstrated the presence of spermatozoa.
  69. Postitive AP and Negative Microscopic and Positive P30
    Semen was identified on_____, however micrscopic examination failed to demonstrate the presence of spermatozoa
  70. Positive AP Negative microscope and negative P30
    No semen was identified on______
  71. Negative AP
    No semen was identified on________
  72. Postitive catalytic color test for blood
    Analysis of _____gave presumptive chemical indications for the presence of blood
  73. Postive catalytic color test and positive Takayama/Teichman
    Blood was identified on______
  74. Positive catalytic color test for blood and Neg Taka/Tiech
    Preliminary tests indicated blood on_____, but further tests could not confirm the identiy of blood
  75. Negative catalytic color test for blood
    Analysis of ____failed to give preumptive chemical indications for the presence of blood
  76. Speicies testing postive results (human antiserum)
    Analysis of ____indicates the presence of human proteins
  77. Speices testing (immunoassay such as hemoglobin or human glycophorin A)
    • Blood was identified on ___, and:
    • human glycophorin A activity was detected.
    • human hemoglobin activity was detected, Blood from upper primates and domestic ferrets may also cause postive reults with this assay.
  78. Chromotographic Immunoassay
    A dye labled______ ______ hemoglobin_____ present in test strip
    monoclonal antihuman hemoglobin antibody is present in the test strip
  79. Chromatographic Immunoassay
    Test area has ______ ______ ______ hemoglobin that captures the Ag-Ab Complex and Ab-Ag-Ab sandwich is formed
    The test area has immobilized polyclonal antihuman hemoglobin that captures the Ag-Ab complext and forms a Ab-Ag-Ab sandwich