My hospital would like to eliminate all glass tubes. Currently OB is sending cord bloods in a 10mL Red Top Clot tube. I was wondering what everyone else out there was doing?

Thank you.

Our OB dept. sends cord blood in an purple EDTA tube and a red 7ml tube (both are plastic).

Same here: a 5ml EDTA tube and a 7 ml red tube (both plastic.)

We get a 7 mL plastic red top tube.

We haven't accepted glass tubes for several years now - for ANY patient (except in absolutely dire emergency).

plastic edta and clot tubes

We get 2 3ml purple tubes. (plastic)

Our OB dept. gets their tubes in the delivery kit. We simply found a kit that included -plastic tubes for cord blood collection. We get plastic 10ml. red tops. But it is only a very recent change, within the last week or so.

We get EDTA only.

Just a completely dumb question here but if the sample is clotted how do you group the babies?

Edit - we get EDTA only

Blood transfusion laboratories always used to use clotted samples until it was realised that EDTA samples were okay to use, even if the Ca++, Mn++ and Mg++ were chelated and that any active complement must have been activated in vivo, and that (almost) every clinically significant antibody could be detected by anti-IgG (or it was an agglutinin).

In those days, we did the cord group (and any other group) by tube, or even on a tile (!) and I suspect that is what is done now with clotted samples (tube, I mean, not on a tile!).

Just a completely dumb question here but if the sample is clotted how do you group the babies?

Edit - we get EDTA only

You sample from the fallout (unclotted) red cells in the bottom of the tube. If the sample is received quickly enough, it is not fully clotted and unclotted cells are sampled and wash thoroughly to make sure fibrin does not interfere.

In those days, we did the cord group (and any other group) by tube, or even on a tile (!) and I suspect that is what is done now with clotted samples (tube, I mean, not on a tile!).

I'm not young enough to never have done a tile group

But if you are using clotted blood I assume you are doing a reverse group using the serum? Baby ABOD are notoriously weak in some cases - could this result is a 'changed' group in the future? Also how do you confirm that the cord blood is indeed foetal? If the sample is clotted you can't do a NaOH test...

I just can't get my head round how this can be safe

Edit - crossposted with Ann.. I'm still not convinced by this... At very least it is a faff

I'm not young enough to never have done a tile group

But if you are using clotted blood I assume you are doing a reverse group using the serum? Baby ABOD are notoriously weak in some cases - could this result is a 'changed' group in the future? Also how do you confirm that the cord blood is indeed foetal? If the sample is clotted you can't do a NaOH test...

I just can't get my head round how this can be safe

Edit - crossposted with Ann.. I'm still not convinced by this... At very least it is a faff

I'm very old and can remember doing IATs on tiles (and in capilliary tubes, come to that)!

Actually, what we would do is wait for clot retraction to get the serum and free red cells. You then test the red cells for the forward group (and, if the baby's group is the same as the mother's, perform the NaOH test), and do the reverse group on the serum.

I agree that most babies have extremely weak/missing ABO antibodies, but this is so whether you are using serum or plasma.

It is also true that the baby's A and/or B antigens can be weak, and yes, this can lead to a "blood group change", but, again, this is true whether or not you are using clotted blood or EDTA blood. EDTA does not enhance the reactions between ABO antibodies and antigens.

Many of the old ways of doing things are not as bad as people make out. For example, it is often easy to see a mixture of IAT-reacting antibodies on a tile, because they tend to react at different speeds, according to their strength. Say you have an anti-D and an anti-Fya, very often the anti-D will come up positive almost straight away, but the anti-Fya comes up much slower.

Have a go using a clotted cord blood, if you can, and see for yourself. You might just be convinced!

We use a 4 ml plastic EDTA tube. We do not perform reverse groups on cord bloods.

Have a go using a clotted cord blood, if you can, and see for yourself. You might just be convinced!

I can see how it would work if the clot hasn't fully formed. But what happens if the clot has fully formed and all you have left is serum? That's my point. All well and good if you catch the sample before it has clotted fully but what if the clot is complete? Surely it's just easier to use EDTA?

Cord blood specimens are sent in an opaque plastic tube (no additive). We are able to retrieve enough cells to thoroughly wash and then type them. We perform a DAT using Anti-IgG only and if it is positive, OB usually orders the first bilirubin on the cord blood specimen. We do not do a reverse grouping on newborns.

Edited November 23, 201113 yr by LCoronado

When using a cord blood sample collected in a clot tube, if the cord blood is nasty - Wharton's jelly, etc. - and the Rh control or DAT control is positive, a capillary sample should be drawn to clarify results.

We've had numerous cases where the doctor, for whatever reason, has requested a retype and repeat DAT on a capillary sample later, and I've not seen a discrepancy between the capillary type and the cord blood type done on a clotted sample. We are also now seeing some patients who were typed as newborns with cord blood samples (didn't used to keep those records in the Blood Bank file) as patients for surgical procedures, and no blood type discrepancies have been identified. We do not, however, use that cord blood type as our second blood type for providing blood products.

Our primary purpose for the cord blood type would be to determine whether or not Mom needs RhoGAM and in some cases, whether or not baby is type A or B with a type O Mom. If you have macroscopic mixed field results for the type (IS) - from intermingling of Mom's cells and baby's - or have problems with the DAT and Rh control cells that aren't fixed by washing the sample cells more, you know you need to recollect a capillary sample. We've done that with only 2 samples in the last 4-5 years.

If we are transfusing an infant, we use capillary or peripheral blood for the type - no backtype is performed until 6 months of age.

I do have a question (maybe I'm just dense today?!)...........what is the NaOH test? Is it a part of routine cord blood testing in the UK?

Edited November 23, 201113 yr by AMcCord

I do have a question (maybe I'm just dense today?!)...........what is the NaOH test? Is it a part of routine cord blood testing in the UK?

It's sodium hydroxide - foetal cells being more resistant, don't lyse. Foetal cells red, maternal cells green/brown. Used to determine if the cord blood is actually foetal when the maternal and baby group are the same.

A dummy question from me here - you say 'fixed by washing more' so do you wash all your foetal cells? I've never worked anywhere that does wash foetal cells (unless there is a problem), but then I've never worked anywhere that uses clotted samples either...

We wash our cells from cord blood samples a minimum of 4 times to remove Wharton's jelly, fibrin, etc. prior to testing. If the controls aren't working, it may be due to contamination with Wharton's jelly that wasn't removed by the initial wash. By washing an additional 2-4 times, we can usually remove the contaminate and get valid results. However, I have done some validation testing on the Echo with cord blood samples from clots using information I got from another Echo user. For that method, you don't prewash the sample. The samples I've run on Echo so far matched our tube testing. Washing may be one of those things that's not really important for most samples, but under the category of "we've always done it that way". Saves problems with some samples, so we keep doing it.

We do an NaOH test here on rare occasion (APT test), but never on cord blood...interesting. Does anyone out there in the US do this on cord blood? We have used it if they want to know if a bloody vaginal sample pre-delivery is all mom's or if baby blood is present. We have also used it, though not very often, on blood diapers or vomit to determine if baby is bleeding internally.

Regarding the use of clotted samples for blood bank testing. In the US we have been a little slower to adopt automation in the hospital transfusion service. In our lab we used manual tube testing until 1997 when we started using manual Gel and did not automate until 2005. Before 1997 virtually ALL of routine blood bank testing was performed using clotted samples. I think use of a clotted sample was pretty much the standard in the US before that time. Even a well clotted sample when centrifuged will yield enough free cells at the bottom of the tube to the forward typing.

I'm not young enough to never have done a tile group

But if you are using clotted blood I assume you are doing a reverse group using the serum? Baby ABOD are notoriously weak in some cases - could this result is a 'changed' group in the future? Also how do you confirm that the cord blood is indeed foetal? If the sample is clotted you can't do a NaOH test...

I just can't get my head round how this can be safe

Edit - crossposted with Ann.. I'm still not convinced by this... At very least it is a faff

We never did (nor do) back types on babies (venous or cord blood).

...... For example, it is often easy to see a mixture of IAT-reacting antibodies on a tile, because they tend to react at different speeds, according to their strength. Say you have an anti-D and an anti-Fya, very often the anti-D will come up positive almost straight away, but the anti-Fya comes up much slower.

Wow Malcolm!! what!!??!! amazing!!

Wow Malcolm!! what!!??!! amazing!!

Yes, it can be quite spectacular. Of course, a mixture of antibodies does not show this phenomenon in all cases, but when it does, it can be a really useful clue.

Just a completely dumb question here but if the sample is clotted how do you group the babies?

Edit - we get EDTA only

Hi, The cord blood provides enough rbc's for testing due to having a higher hgb compared to someone with a hgb of 3 and it is really nasty to pipet out the rbc's. I would like EDTA,although sometimes the clot is used for

bili and thyroid testing. Happy Thanksgiving!