Direct and Indirect Antiglobulin Testing 8.3

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Direct and Indirect Antiglobulin Testing 8.3
2010-09-14 11:02:31
Direct indirect antiglobulin testing blood bank unit NSHS MLT

Direct and Indirect Antiglobulin Testing, Blood Bank Unit 8.3
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  1. Blood banking techniques are concerned with what two antibodies found in serum.
    • IgG
    • IgM
  2. What does Marcellus Wallace look like?
    • Black
    • Bald
    • Not a bitch
  3. __________ antibodies are not capable of physically clumping a suspension of red blood cells.
  4. what type of antiglobulin recognizes one epitope?
    monoclonal antiglobulin
  5. what type of antiglobulin recognizes different epitopes?
  6. where are antigens found?
    on RBC membrane
  7. blood banking concerns itself with antigens found on what two cell membranes?
    • Red cell
    • White cell
  8. this is an antibody prepared in rabbits that is directed against human antibodies.
    Antihuman Globulin (AHG)
  9. what are two other names for antihuman globulin?
    • Coomb's antisera
    • Anit-human sera
  10. this is a series of proteins in circulation that when activated can cause disruption of bacterial and other cel membranes.
  11. term used to denote that red blood cells are coated with antibody or complement.
  12. this is inactivating an antibody by reacting it with an antigen against which it is directed.
  13. the process used to recover antibdies off of sensitized red blood cells.
  14. this is a substance that will enchance antigen-anitbody interactions.
  15. this poteniator reduces the ionic strength of a red cell suspension medium.
    Low Ionic Strength Solution (LISS)
  16. what potentiator increases the affinity of the antigen for its corresponding antibody.
    Low Ionic Strength Solution (LISS)
  17. what potentiator is a water soluble, linear polymer that produces very specific reactions?
    polyethylene glycol (PEG)
  18. what potentiator removes water to concentrate antibody?
    polyethylene glycol (PEG)
  19. what percent albumin is used as a potentiator?
  20. what potentiator is a colloidal diluent that works best for Rh antibodies?
    22% albumin
  21. the original test principle of antihuman globulin sera was developed in 1908 by who?
  22. use of the antihuman globulin sera test was established in 1945 by what three people?
    • Coombs
    • Mourant
    • Race
  23. AHG is used to detect RBC's sensitized by _________ antibodies.
  24. in 1957, __________ discovered antiglobulin reagent could be used to detect the sensitization of red blood cells with complement.
    Dacie et al
  25. AHG can detect _________ which is bound to the RBC membrane.
  26. AHG led to the finding of what certain blood group systems demonstratable only by antiglobulin techniques.
    • Kell
    • Duffy
    • Kidd
  27. what are the two classes of AHG?
    • monoclonal
    • ploycolonal
  28. AHG classes are based on what?
    how it is manufactured
  29. what are the subdivisions of AHG?
    • monspecific
    • polyspecific
  30. AHG is subdivided by what?
    what the antiglobulin is directed against
  31. what is the technology used for monclonal AHG?
  32. what type of AHG produces an immortal cell line that produces a specific antibody?
    monoclonal AHG
  33. what are the three advantages of monoclonal AHG?
    • higher titer than piolyclonal
    • no batch variation in sera production
    • not subject to cross-reactivity
  34. what are the three disadvantages of monoclonal AHG?
    • over-specificity
    • overly sensitive
    • complement fixation may not be detected
  35. what type of AHG is produced by more than one spleen lymphocyte that produces immunoglobulin?
    polyclonal antisera
  36. polyclonal sera made from these animals will be directed against what?
    multiple epitopes
  37. what are the two advantages of polyclonal AHG?
    • more likely to pick up genetic variants
    • cheaper
  38. what are the two disadvantages of polyclonal AHG?
    • low specificity
    • low titer
  39. Disadvantages of of monoclonal reagents may be overcome by what type of AHG?
    monoclonal/polyclonal blends
  40. what are the two types of AHG blends?
    • blends of different monoclonal reagents
    • blends of monoclonal and polyclonal reagents
  41. polyspecific AHG is a blend of what three globulins?
    • Anti-IgG
    • Anti-C3b
    • Anti-C3d
  42. polyspecific AHG detects red cells that have been sensitized with ____ antibodies or complement.
  43. what are the five basic types of monospecific AHG?
    • Anti-IgG
    • Anti-C3
    • Anti-C3b
    • Anti-C3d
    • Anti-C4
  44. the principle of the Direct Antiglobulin Test (DAT) is to detect ________ sensitized red cells.
  45. The Direct Antiglobulin Test (DAT) is a ______-stage test.
  46. in what antiglobulin test are steps taken to minimize in-vitro red cell sensitization?
  47. blood for DAT is collected using what anticoagulant?
  48. what temperature should DAT samples be tested at?
    room temp
  49. The DAT is used to determine what four condtions?
    • hemolytic disease of newborn
    • auto-immune hemolytic anemia
    • investigation of trasfusion reaction
    • drug-induced red cell sensitization
  50. For DAT cells are first washed with saline how many times?
    three to four
  51. true or fase
    washing cells for DAT may be done as part of the initial 2-5% cell suspension for ABO testing.
  52. what is the purpose of washing cells in the DAT?
    to remove unbound serum globulins
  53. one drop of what ratio dilution of human serum can neutralize one drop of antiglobulin serum.
  54. for DAT washed cells must be completely _________ in the tube of saline.
  55. wasing in DAT must be done ______ and _________ to avoid elution of the antibody.
    • rapidly
    • uninterrupted
  56. what should be decanted after each wash of cells?
  57. durring which washes should you leave a residual amount of saline to resuspend the cell button?
    wash 1 and 2
  58. when washing cells saline should be added in a ________ stream.
  59. residual saline from washing can dilute what?
    antiglobulin serum
  60. what should be done after the third and final wash?
    • decant saline
    • blot tube dry
  61. for the DAT procedure a 2-5% saline suspension should be prepared from _______ cells.
  62. how many drops of 2-5% saline suspension should be added to a tube for DAT?
    one drop
  63. how many drops of antiglobulin serum should be added to the washed cell button in DAT?
  64. Durring the DAT when may may three additional washing need to be performed?
    after one drop is placed into the tube
  65. what is the AHG to cell ratio for DAT?
  66. in the DAT procedure, after centrifuging, read for __________ while gently resuspending the cell button.
  67. the DAT should be read ____________ and ____________.
    • macroscopically
    • microscopically
  68. a positive, in the DAT, procedure indicates that cells were sensitized by _________ and/or ___________ in vivo.
    • antibodies
    • complement
  69. if checks cells fail to agglutinate in the tubes what is indicated?
    • test tube does not have active antiglobulin sera
    • test is not valid and must be repeated
  70. how many tubes are used for the DAT battery/panel
  71. for the DAT batter negative results must be verified how?
    • microscopically
    • confirmed with check cells
  72. the principle of the indirect antiglobulin test (IAT) is to detect ______ sensitized red cells.
  73. how many stages are the the IAT procedure?
  74. what is the sample used in the IAT?
  75. what are the three applications of the IAT test?
    • compatibility testing
    • antibody detection and ID
    • Detection of antigens on RBC
  76. what antiglobulin test is used to detect antigens on RBCs not demonstrated by other typings?
  77. what are four antigens that are tested by IAT?
    • Weak D
    • Kell
    • Duffy
    • Kidd
  78. the reagent used for IAT is commercially prepared _________ specifically chosen for the broad range of antigens expressed.
    red cells
  79. commercially prepared red cell reagents used in IAT are commonly called __________ cells.
  80. how many types of screening cells are generally used in IAT?
    two or three
  81. in IAT ___ drop of screen cell suspension is mixed with ___ drops of serum
    • 1
    • 2
  82. without the use of a potentiator, how long should IAT samples be incubated at 37oC?
    30-60 min
  83. use of LISS reduces incubation to ______ minutes vs. 30-60 minutes.
  84. most IgG antibodies react optimally at what temperature?
  85. what temperature does complement activation occur best at?
  86. after the incubation stage red cells should be washed ___ times in saline
  87. In IAT, after incubation and wash, how many drops of antiglobulin serum should be added to the washed cell button?
  88. in the IAT if cells agglutinate ni the antiglobulin serum what reaction is indicated?
  89. a positive reaction in IAT, indicates that a ______________ reaction occurred durring the incubation.
  90. no agglutination in the antiglobulin sera indicates what reaction in IAT?
  91. if negative IAT, __________ must be added to the tubes to confirm the activity of the antiglobulin serum.
    check cells
  92. bacterial contamination of cells leading to T-activation can cause what type of false result in AHG testing?
  93. Anti-T occurs _________ in everyone's serum
  94. All cells with activated T sites ___________.
  95. saline and glassware contaminated with silica particles, or other debris and dirt can cause what type of false result in AHG testing?
  96. over-centrifugation can cause what type of false result in AHG testing?
  97. cells that are positive by the direct antiglobulin test cannot be used in a _______ test.
  98. cells that are positive by the direct antiglobulin test cannot be used in an indirect test, why?
    cells would always be positive no matter what serum those cells were mixed with
  99. what testing method can a false positive be caused by refigerated specimens.
  100. serum may contain _______ autoantibodies capable of sensitizing red cells with complement at refigerator temperatures and sometimes even at room temp.
  101. what type of antibodies may be missed if anti-coagulated plasma or old serum is used.
  102. neutralization of the antiglobulin due to poor wasing can cause what type of false result in AHG testing?
  103. contamination of the reagent with human globulin can cause what type of false result in AHG testing?
  104. elution of the antibody during the wasing can cause what type of false result in AHG testing?
  105. use of an incorrect incubation temperaute can cause what type of false result in AHG testing?
  106. use of an incorrect incubation temperature will cause antibody activity to ________.
  107. improper concentration of cells and serum can cause what type of false result in AHG testing?
  108. omitting the antiglobulin serum can cause what type of false result in AHG testing?
  109. under centrifugation can cause what type of false result in AHG testing?
  110. AHG is store at what temperature when not in use?
  111. the specificity of antiglobulin reagents should be tested how often?
  112. Anti-IgG activity is confirmed by the use of ____ coated cells
  113. Anti-Complement activity is confirmed by the use of __________ coated red cells.
  114. AHG is test against _______ cells to be free of antibody and complement daily.
  115. This is performed daily before use of reagent red cells.
    quality control
  116. what controls must be used for IAT and DAT testing?
    • positive
    • negative
  117. what type of cells must be used for weak expression of antigens.