DONATH-LANDSTEINER (D-L) ANTIBODY TEST Principle Procedure Result

DONATH-LANDSTEINER (D-L) ANTIBODY TEST

Principle

Procedure

Result  

Introduction

Paroxysmal cold haemoglobinuria (PCH). is caused by a "biphasic' auto antibody which is IgG in nature. When incubated with red cells at 0°C this antibody binds to the red cells. Lysis occurs when this antibody-red cell complex is incubated at 37°C in the presence of complement. 

Specimen 

Collect 5 ml blood in each of two plain tubes. Immediately place both the tubes at 37°C. 

Technique

1. Place one tube in crushed ice for 30 minutes (Tube 1).

2. At the same time, place the second tube at 37°C for 1 hour (Tube 2).

3. At the end of 30 minutes, transfer the tube from the ice-bath to the incubator at 37°C, and incubate for 30 minutes.

4. Centrifuge both tubes at 200 g for one minute and compare the supernatant in both the tubes.

Results  

The test is positive if the tube 1 shows haemolysis. The other tube incubated at 37°C serves as a control and should show no evidence of haemolysis.