Direct Coombs Profile by Gel

[johna]

Is anyone using the Provue or manual gel for direct Coombs' profiles?

Since there is no anti-C3 gel card we have been advised that anti-C3 results can be recorded as a default result if the polyspecific is positive and the anti-IgG is negative. In other words a 2+ with polyspecific and a negative with anti-IgG automatically indicates that anti-C3 results should be recorded as 2+.

I understand that part, but what if the anti-IgG results are 2+? I assume that you are then bound to perform a tube DAT with anti-C3. This somewhat defeats the purpose of using gel for DAT profiles since the great majority of polyspecific-positives will also be anti-IgG-positive and require tube testing. Also I would guess that your gel reactivity grading is routinely going to exceed what you will see in a tube test.

[janet]

We used to do the IgG portion by gel and the C3d by tube....now we use the DIAMED DAT card purchased through ORTHO, manufactured in ?Europe. It has 3 wells-IgG/C3d/buffer control. The cards are wonderful and not much more expensive than if we used the polyclonal card before going to the expanded DAT.

[Seveets]

We use the cards for IgG and tube testing for complement

[labgirl153]

That's terrific Janet...hadn't read of this product...probably because we (Americans) don't partake of the foreign product market so much as our northern neighbors.

The DAT by gel and C3d by tube isn't really an extra step for us, since positive DATs are few and far between at my lab. If we do get a positive, it's because we only perform them when the auto control is positive while investigating a suspected antibody, or as part of a transfusion reaction workup.

However, sounds like JohnA has a larger facility and encounters this problem more often? Am not sure what his set up is. Perhaps the gel card you mentioned Janet, would be a feasible alternative for him.