Procedure For Making Student Specimens

[Mabel Adams]

Does anyone have any procedures that they can share for making up student specimens, either spiking plasma samples with antibodies but even more so, making up specimens for doing eluates?  If there are some on this site already, sorry for the repeat, but I can't find them.

[Emwilson7]

Do you have a reference lab that could send you any antibody positive plasma aliquots?

 

As for eluates, you could always incubate some anti-D with D positive red cells. I usually just use cells from a patient sample with a warm auto for training on eluates.

Edited May 20, 2013 by Emwilson7

[Mabel Adams]

Most of our antisera are monoclonals so I hesitate to use them to make pos DATs for elution.  We were able to use commercial anti-Fyb to make one today but it would be more cost effective to use donor or patient antibodies.  But how much antibody plasma/antisera should we add to the cells?

[Eagle Eye]

we do the same...take O positive donor segment(or you can also use O Pos patient) and add anti-D.

2-3 segment and add 2 drops of anti-D...increase it accordingly...Should work.

Edited May 7, 2013 by Eagle Eye

[AMcCord]

Adding 10 drops of Check Cells to three donor segments makes a nice elution sample. The DAT is pretty weak with mixed field and the eluate is usually a nice 1-2+ for anti-D (I use a monoclonal blend anti-D).

 

Spike plasma with 6-7 drops of anti-Jka and Fya, 8-9 drops of s and S respectively - these should be less than 2+ to +/- depending on whose antisera you use. The monoclonal Rh antiseras are not very realistic since you may get IS reactions depending on how much you use - 1 or 2 drops should be plenty. Anti-K takes about 1-2 drops. With those we have a discussion about how we might see an antibody early in it's formation as IgM vs IgG and I make sure they understand that their sample is not typical of what patients usually do. I never discard outdated antisera, so I have quite a stash for student torture education. 

 

If I have a good antibody in a patient sample I try to freeze some of it in the ultra-low freezer. I like type O samples best because I can pair them with cells from an ID panel that lack the corresponding antigen. I do not mix the plasma sample with the cells. That way I can have the student do a full workup with type, screen, ID, crossmatch, etc. If I screw up and pick an antigen positive cell......then they get a positive auto - another opportunity for  education!

[jill]

Does anyone have any procedures that they can share for making up student specimens, either spiking plasma samples with antibodies but even more so, making up specimens for doing eluates?  If there are some on this site already, sorry for the repeat, but I can't find them.

To demonstrate mixed field in forward typing, mix together the contents of one segment

from a grp A blood unit and one segment from a grp O blood unit.

[ChrisH]

For my mixed field, I will take about 7 to 8 drops of either A or B cells and add 2 drops of screening cells. This will show a nice weak mixed field.

To demonstrate mixed field in forward typing, mix together the contents of one segment from a grp A blood unit and one segment from a grp O blood unit.

[ChrisH]

I like this, will have to check this one out.....did not think about using check cells....

Adding 10 drops of Check Cells to three donor segments makes a nice elution sample. The DAT is pretty weak with mixed field and the eluate is usually a nice 1-2+ for anti-D (I use a monoclonal blend anti-D).

 

[Mabel Adams]

AMcCord, how much patient plasma are you using when you spike it with the drops of (I assume commercial, human-source) anti-Fya or Jka?

[AMcCord]

Mabel - I'm spiking a 2 mL sample of plasma. And yes, I'm using outdated commercial antisera for the anti-Fya and -Jka.

[Jane]

I have always used expired antisera as well.  Usually just a drop or two will do it.  We used to make our own QC material by this same method, aliquot, and freeze it.

[amym1586]

Is there a way to make a fake Lui Freeze ?

[AMcCord]

Is there a way to make a fake Lui Freeze ?

Do you have collect cord blood samples?  Cord red cell samples from A or B babies of type O moms (with pos DAT not due to other alloantibodies) can be preserved in Alsevers for nice student project samples. I've faked samples for immediate use by combining A or B cells from donor segment samples with type O plasma. I wash some of the excess plasma away before I give the sample to the student to work with. I don't have a specific recipe - just add a splash of plasma to cells from a couple of segments, then check a drop for a pos DAT.

[Dr. Pepper]

amym1586, on 22 Jul 2014 - 5:19 PM, said:

Is there a way to make a fake Lui Freeze ?

I start off my students doing a mess of typings on random "just in case" tubes from the main lab about to be discarded - CBC and coag tubes. You don't need to do 40 typings to learn how but this also gives them good practice making suspensions, reading reactions, figuring out which end of the pipet to hold etc. Save the specimens. Next day, I tell them they will do one typing that will take all day. I show them on paper what they would have done to get to that point: O on front type, A or B on back type, couldn't get that "missing" back type cell to react with a cold back type. You should have plenty of O and A specimens, maybe a few B/AB. Make pools of each type and wash. To make your weak "patient sample", spike 2-3 ml of washed packed O cells with 10 drops of A or B cells. They also do the procedure on straight O and A (or cells. It works with either human source anti-A or -B (saved from the previous day's specs) as well as reagent monoclonals. I probably should spike the mock patient sample with fewer cells as you will probably adsorb out all the antibody, but they get the point and I want it to work.

 

Other student stuff:

 

A2 or A2B with anti-A1: spike a real A or AB serum with reagent anti-A1.

 

O with weak anti-A+B: make a 12-tube serial dilution of O serum. Test each dil against A and B cells in the cold. Find the dil that gives you a w+ or 1+ in the cold. Make sure that dilution is not reacting at IS. Make up more of that dilution and give them O cells and that for their typing - the goal will be to get them to do a cold back type.

 

Typing with unexpected abs in serum: Spike your serum with reagent anti-c etc or a patient ab that will react at IS. 

 

Review your panels often. If someone has an antibody, scrounge up the stored tubes, even coags, from other depts if they save them, then pool and freeze to torment future students down the line. Freeze some specs with nice rouleaux.

 

Make DAT positive cells for eluates by adding reagent anti-D to Rh+ cells as others have suggested. Our QC reagent ab has anti-A, -B, -D, -c. After the kit ODs I use it to get a "panagglutinin" by sensitizing D+c+ cell, or auto-anti-c by sensitizing D- cells.

 

Transfusion reactions: Add 1 drop check cells to 12 or more drops non-coated cells to give mixed-field agglutination.

 

I teach PeG autoadsorption by starting them with a pseudo-patient with the above "panagglutinin" on cells and in serum. They then use some frozen samples with anti-K and a couple of old CBC tubes that I've typed and are K- for their patient serum/plasma and cells (there's no "autoantibody" in the sample now but they'll never know that).

 

Take advantage of fresh real specs when you have them (known weak Ds or weak subgroups), and in particular freeze specs with cool stuff like and-Sda or RG/Ch that you can do urine or plasma neutralization with.

 

I also take them to watch a unit being hung, show them our QA process, involve them in audits and whatever periodic QC comes due while they're in the dept.

[Malcolm Needs ☆]

I just LOVE the word "torment" Phil.

 

A teacher after my own heart!!!!!!!!!!!!!!!!!!!!