Antibody Screen Method

Which patient sample is used for the antibody screens?

Plasma or serum

What is the patient sample mixed with in the antibody screens?

O screening CELLS which have KNOWN antigen profiles

What are we looking for in the antibody screen?

AGGLUTINATION or hemolysis = this indicates the presence of an antibody FOR THAT ANTIGEN

What are the 4 testing phases of the Antibody Screen IN ORDER?

1. Immediate Spin (IS)

2. 37C

3. WASHING 3x

3. AHG

4. CHECK CELLS ONLY ON NEGATIVE AHG

At what temperature is Immediate Spin done?

ROOM TEMP

Which antibody type does Immediate Spin detect for?

IgM

What is done in the Immediate Spin?

Patient plasma + Reagent RBCs (O cells) aka I II III

CENTRIFUGE 20 sec 3500rpm

What antibodies are detected for in the 37C phase?

IgG

At what temperature is the 37C phase done?

37C BODY TEMP

Which CRITICAL enhancement media is added in the 37C phase before incubation?

LISS reagent

LISS IS HOT (37C)

What is done in the 37C phase?

1 . Add LISS to mixture

2 . INCUBATE FOR 10 MIN at 37C

After 37C phase and BEFORE AHG, what is done?

WASHING 3 x

How is washing done after the 37C phase?

Filling tube with saline, centrifuging, dumping water WHILE KEEPING BUTTON IN TACT

How many times do we wash before the AHG phase?

Washing for 3 times (1 minute centrifugation between each wash)

FINAL WASH: FULLY DECANT (tap twice)

Finally add 2 drops AHG reagent

Which antibodies are detected for in the AHG phase?

IgG antibodies

Which reagent is added in the AHG phase?

2 drops of GREEN Reagent / Coomb’s Reagent

What is the AHG phase detecting specifically?

Sensitized RBCs

What are sensitized RBCs in the AHG phase?

RBCs that are coated with IgG

What is added ONLY to NEGATIVE AHG tests?

Check Cells which validate the negative

What should be seen with Check Cells if the AHG is TRULY NEGATIVE?

CHECK CELL CLUMPING

The RBC Reagents/Screen Cells will be numbered in what way?

ROMAN NUMERALS

I II III

What is known about the RBC Reagents/Screening Cells?

FULL ANTIGEN PROFILE

Cells from group O individuals

How do the RBC reagents/Screenings Cells allow for DOSAGE?

They can have HOMOZYGOUS cells

Homozygous & Heterozygous, but homozygous contributes to dosage

If Screening Cell II is (M+N-) and patient has Anti-M what does that mean?

MM HOMOZYGOUS therefore reacts strongly with Anti-M in the patient plasma

So in HOMOZYGOUS screening cell and patient antibody reactions, what grading can be seen?

3+ or 4+ TYPICALLY

In HETEROZYGOUS screening cell and patient antibody reactions, what grading can be seen?

1+, 2+, MAYBE 3+

What is the specific name of the Antigen Profile Sheet for the RBC reagent/Screening Cells?

Antigram

Which is the main enhancement reagent used before incubation in the 37 C phase?

LISS

LISS IS HOT

What is the PURPOSE of the washing step before AHG?

Washing is done to remove any IgGs that are NOT actually bound to RBCs