We had a case where we got O negative on the cord blood sample and O positive on a heelstick of the baby. Results were rechecked and were the same. Results were carried out through IgG. Mom is O negative. The sample is labeled with the correct label. Besides the nurse collected the wrong patient, any ideas why this happened.

Could be maternal blood.  Have tried testing the red cells with NaOH?

I have seen this so many times and have always come to the conclusion that it was a mislabeled sample.  Let us know what you find.  

We once had a mismatch due to a correctly labeled but Incorrectly drawn cord blood? To be honest I did not understand the explanation on how it was, or could be drawn incorrectly?!

12 hours ago, Malcolm Needs said:

Could be maternal blood.  Have tried testing the red cells with NaOH?

Would you please explain why we can different the maternal blood and fetus's blood by using NaOH? Thanks!

If you put a drop of blood on something like a filter paper, and then add a drop of 1M NaOH, if it is adult blood, after a couple of minutes it will turn a sort of yellow/brown colour, as the Hb is denatured by the alkaline, whereas, if it is blood derived from the baby (including cord blood), the red cells will stay red, as HbF is not denatured by the alkaline for much longer.

It is rather like doing a Kleihauer, but by "bucket chemistry", as it is known!  

2 hours ago, Malcolm Needs said:

If you put a drop of blood on something like a filter paper, and then add a drop of 1M NaOH, if it is adult blood, after a couple of minutes it will turn a sort of yellow/brown colour, as the Hb is denatured by the alkaline, whereas, if it is blood derived from the baby (including cord blood), the red cells will stay red, as HbF is not denatured by the alkaline for much longer.

It is rather like doing a Kleihauer, but by "bucket chemistry", as it is known!  

Nice !!! Old School.

3 hours ago, Malcolm Needs said:

If you put a drop of blood on something like a filter paper, and then add a drop of 1M NaOH, if it is adult blood, after a couple of minutes it will turn a sort of yellow/brown colour, as the Hb is denatured by the alkaline, whereas, if it is blood derived from the baby (including cord blood), the red cells will stay red, as HbF is not denatured by the alkaline for much longer.

It is rather like doing a Kleihauer, but by "bucket chemistry", as it is known!  

Works well when someone brings you a 'red' diaper or burp rag and wants to know if you can do a blood type to see if the blood is mom's or baby's.

(Doesn't work worth a darn though for cherry/red colored meds or drinks )

1 hour ago, AMcCord said:

Works well when someone brings you a 'red' diaper or burp rag and wants to know if you can do a blood type to see if the blood is mom's or baby's.

(Doesn't work worth a darn though for cherry/red colored meds or drinks )

I knew this sounded familiar!  

8 hours ago, Malcolm Needs said:

If you put a drop of blood on something like a filter paper, and then add a drop of 1M NaOH, if it is adult blood, after a couple of minutes it will turn a sort of yellow/brown colour, as the Hb is denatured by the alkaline, whereas, if it is blood derived from the baby (including cord blood), the red cells will stay red, as HbF is not denatured by the alkaline for much longer.

It is rather like doing a Kleihauer, but by "bucket chemistry", as it is known!  

We do this test on all Rh (weak D) negative cord blood specimens from babies with Rh negative moms -- just to make sure that it is baby blood and that mom doesn't need RhIG.

2 hours ago, TreeMoss said:

We do this test on all Rh (weak D) negative cord blood specimens from babies with Rh negative moms -- just to make sure that it is baby blood and that mom doesn't need RhIG.

So did we.

What was the DAT result?  If it was weakly or 1+ positive, you cannot accept the Rh result. At our facility, if the mom is Rh Neg and the baby initially types Rh Neg, with the DAT positive, we cannot perform the weak D; we have to send it out to the Reference Lab for testing.  If the antigen sites for D are coated already by anti-D, then the baby might type as Rh Neg. The cells need to be eluted,  EGA can be used to knock off any antibody and do the blood typing.  If the doc doesn't want the baby stuck, we turn out Rh Indeterminate, and recommend the baby be typed later.

Ok, first, DAT was negative. I did the NaOh test, we only had 0.1 N. I ran a cord and adult for comparison.The cord in question did look more like an adult sample then a cord sample. Mother is O neg, so maybe it was her blood?

 It seems to me, a long time ago, in a lab far away, we would heelstick the babies if we got Rh negative and the mom was Rh negative. To make sure the baby's type was correct and if mom needed RhIg or not.