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Characteristics of IgM

Reacts at Cold, Fix complement, Pentamer (10 binding sites), Intravascular Hemolysis, Primary Response antibody

Characteristics of IgG

Reacts at Warm, Fix complement, Monomer (2 binding sites), Extravascular or Intravascular Hemolysis, Secondary Response antibody

Define Zeta Potential

Cloud of Ions surrounding the negatively charged RBC membrane

Post Zone affecting Agglutination

too much antigen in test system, affects lattice formation

Pro Zone affecting Agglutination

too much antibody in the test system, can prevent lattice formation

Enhancement media

Can be used during 37C incubation phase to assist in detection after IS

Anti-Human Globulin

Crosslinks antibodies attached to RBC at the Fc region

LISS

Decreases the ionic strength which results in decrease of zeta potential

Polybrene

Ammonium polymer that causes nonspecific RBC aggregation

Polyethylene Glycol (PEG)

Promotes antibody-antigen interactions by reducing the volume of the medium via steric exclusion of water molecules

Proteolytic Enzymes

Results in release of sialic acid and decrease in RBC membrane negative charge

Monoclonal Antibodies

Derived from Single Antibody Producing cell

towards a specific epitope of an antigen

Polyclonal Antibodies

Derived from more than one antibody producing cell

towards multiple epitopes of an antigen

Lectin

Extracts directed towards specific carbohydrate structures on RBCs

Prepared from plant extracts

Why are Naturally occurring antibodies developed

From immune stimulation from chemically similar environmental antigens

Universal Red Cell Donor

O neg

Universal Plasma Donor

AB

Immunodominant Sugar for Type A Blood

N-acetyl-D-galactosamine

Immunodominant Sugar for Type B Blood

D-galactose

Immunodominant Sugar for Type O blood

L-fucose

Immunodominant Sugar for Type AB Blood

N-acetyl-D-galactosamine and D-galactose

Which Lectin is used to detect presence of H antigen

Ulex europaeus

Which Lectin is used to detect presence of A1 antigen

Dolichos biflorus

What are the Three Mechanisms for Weak D expression

Partial D, C Trans, Genetic Weak D

What is the criteria for ABO/Rh testing

Must have reaction strength >= 2 and no Mixed Field

Hemolysis is considered a

Positive reaction in Antibody Screening

Direct Antiglobulin Test

Detects the presence of antibodies that already bound to the patients RBCs in vivo. NO Incubation or Enhancement due to currently bound antibodies

What situations would you perform a DAT

HDFN, Transfusion Rxn, Autoimmune Hemolytic Anemia, Drug Associated with Hemolysis

Indirect Antiglobulin Testing

Test that detects patient antibodies that have the potential to bind to red cells in vitro (tube)

Types of IAT

Antibody Screen, RBC Crossmatch, Antigen Typing

What are Coombs Control cells and what do they do

RBC reagent coated in IgG used to detect to see if the AHG reagent is working if there was a negative result during PEG/AHG phase

What would cause non-reactive Check Cells

Unbound antibody Present (Prevents binding to AHG)

Forgot to add AHG

What specimen type can be used to observe hemolysis

Serum because plasma tubes bind to the magnesium and calcium required for complement fixation therefore preventing hemolysis

What is the Criteria for Electronic Crossmatch eligibility

No Clinically Significant Antibody

No History of Clinically Significant Antibody

ABO has been tested at least Twice

Whole Blood Derived Platelets are given based on

ABO/Rh compatibility

Platelet Apheresis platelets are given based on

Plasma Compatibility

How long should the patient sample and donor unit segment be kept after pre-transfusion testing

7 days

Strongest to Weakest H antigen Expression on ABO Cells

O > A2 > B > A2B > A1 > A1B

Frequency Type O

Whites: 45

Blacks: 50

Frequency Type A

Whites: 40
Blacks: 26

Frequency Type B

Whites: 11
Blacks: 20

Frequency Type AB

Whites: 4

Blacks: 4

What percentage of Rh negative individuals will make an Anti-D antibody when given Rh positive blood

80 - 100%

ABO antigens are fully expressed by

2-4 years old

What must be present on a Compatibility Label

The recipient's two unique identifiers (usually a name and a hospital number)

Donor unit number

Interpretation of compatibility tests if performed