One of our labs recently came up with a question as to whether it was acceptable to run the "weak D" test without an Rh control and accept the results if they are "negative". In a situation in which the "weak D" test is "positive" they would repeat the test along with an Rh control to validate results.

As far as I'm concerned I don't see any problem with this and the CAP inspection checklist does not seem to address the issue specifically. We do not get AABB inspected so I'm not sure if they do or not.

Any comments would be appreciated.

The only time we require a control during the wD test is if the result is positive. The control can be either repeating the wD test with control sera or do a DAT. As long as the wD test is negative no control is needed as indicated in the package insert from the anti-D reagents we use.

Depending on the training level of your staff, using a control routinely is an option so there is no chance to "forget" to go back and run one.