Antibody Screening Methods

Antibody Screening

• Purpose: to detect unexpected antibodies in a patient's blood

Categories of Unexpected Antibodies

• Not mentioned in the text

How is Antibody Screening Performed?

• Method of antibody screening: Tube Method
• The tube method involves:
  • Immediate Spin Phase
  • 37°C Incubation Phase
  • Antiglobulin Phase

Tube Method

• Immediate Spin Phase: initial centrifugation of the sample
• 37°C Incubation Phase: incubation of the sample at 37°C to enhance antibody detection
• Antiglobulin Phase: addition of antiglobulin to detect IgG antibodies

Grading of Agglutination Reactions

• Turgeon method:
  • 0: no aggregates
  • mf: few isolated aggregates, mostly free-floating cells, supernatant appears red
  • Weak (+/-): tiny aggregates, many free RBCs, turbid and reddish supernatant
  • 1+: a few small aggregates just visible macroscopically, many free erythrocytes, turbid and reddish supernatant
  • 2+: medium-sized aggregates, some free erythrocytes, clear supernatant
  • 3+: several large aggregates, some free erythrocytes, clear supernatant
  • 4+: all the erythrocytes are combined into one solid aggregate, clear supernatant
• Harmening method:
  • 0: no agglutination or hemolysis
  • W+: tiny agglutinates, turbid background
  • 1+: small agglutinates, turbid background
  • 2+: medium-sized agglutinates, clear background
  • 3+: several large agglutinates, clear background
  • 4+: one solid agglutinate

Direct Coomb's Test

• Procedure:
  • Steps 1-6 not mentioned in the text
• Interpretation:
  • Positive: agglutination/clumping of red blood cells
  • Negative: no clumping or agglutination

Factors Affecting Agglutination

• 7 factors mentioned, not specified in the text

Gel Method

• Procedure:
  • Steps 1-9 not mentioned in the text