For more than 20 years, I have not worked with a microscope in blood bank, is there any reason we should or should not use microscope in blood banking?

Apart from those doing the Kleihauer test in the Blood Bank (and this should be done by Haematology, as they have more experience of microscope work from cell morphology), there is NO reason to use a microscope in the Blood Bank (see Peter Issitt on this issue!).

Ha ha I can just imagine handing over the Kleihauers - it's hard enough to get someone to sit down and do a manual diff on a myeloperoxidae patient (we have Advia 2120s sadly...)

I find it useful for distinguishing weak mixed field reactivity sometimes, as well as rouleaux.I don't endorse routine examination of negative AHG reactions.

All of our package inserts say to read macroscopically only. So we only use ours for the Fetal Maternal Hemorrhage Bleed Screen test. And to occasionally to look for rouleaux.

Pretty much only to verify rouleaux, such as when doing a IS XM for a patient whose plasma came out of the fridge cold.

 

Scott

All of our package inserts say to read macroscopically only. So we only use ours for the Fetal Maternal Hemorrhage Bleed Screen test. And to occasionally to look for rouleaux.

 

Don't you have any of the reagents where the inserts include "use of an optical aid" as acceptable or recommended?

 

Any time I've broached the topic of microscopic reading and its controversy this is brought up.

Don't you have any of the reagents where the inserts include "use of an optical aid" as acceptable or recommended?

 

Any time I've broached the topic of microscopic reading and its controversy this is brought up.

 

Optical aid can be defined as an agglutination viewer with a magnifying mirror.  It does not necessarily mean a micoscope is required.

we use microscope for all our DAT to detect mix field reaction. 

Optical aid can be defined as an agglutination viewer with a magnifying mirror.  It does not necessarily mean a micoscope is required.

 

I completely agree with you, but it also doesn't rule out the use of a microscope. I am happier with the reagents that specifically say you shouldn't use microscopy to grade reactions.

 

When I said broached, I meant with my own staff.

Agree with Sandy L; agglutination viewer seems to be fine.

And also goodchild; I believe that's really the intent is to base your interpretation/result on the macroscopic reading. Nothing prevents a tech from using a microscope, as long as they are following the manufacturer's instructions on how to result the test macroscopically only. The risk is that you see something in the microscopic that then leads a tech to chase a rabbit trail that wastes time.

Simply could NOT agree more Terri.

 

Peter Issitt, in the various editions of Applied Blood Group Serology is quite definite on this subject (as I have posted many times before).

Same as Terri

Thank everyone for your honest opinions. 

I have been following this topic because.... I have worked in TM for 14 years and have ALWAYS used a microscope to read negative reactions!  Four different hospital labs - all use a microscope.

 

I can't be the only one?

s

Agree with Sandy L; agglutination viewer seems to be fine.

And also goodchild; I believe that's really the intent is to base your interpretation/result on the macroscopic reading. Nothing prevents a tech from using a microscope, as long as they are following the manufacturer's instructions on how to result the test macroscopically only. The risk is that you see something in the microscopic that then leads a tech to chase a rabbit trail that wastes time.

 

 

Simply could NOT agree more Terri.

 

Peter Issitt, in the various editions of Applied Blood Group Serology is quite definite on this subject (as I have posted many times before).

 

I have been following this topic because.... I have worked in TM for 14 years and have ALWAYS used a microscope to read negative reactions!  Four different hospital labs - all use a microscope.

 

I can't be the only one?

s

 

From the Immucor GammaClone Anti-IgG (murine monoclonal) insert:

 

Under materials: "an optical aid such as a hand lens, a concave mirror, or a microscope."

 

In test methods for both DAT/IAT: following centrifugation, "Resuspend the red blood cells by gentle shaking and examine for agglutination. Negative reactions may be examined with an optical aid. Record results."

 

Under interpretation: "Agglutination of the test red blood cells in either the direct or indirect antiglobulin test constitutes a positive test result."

 

I didn't see the word macroscopic in the entire document.

 

I'm pointing this out not because I agree with it, in reality I am averse to the use of the microscope. When I saw Malcolm's post about it and reference to Issitt several years ago, I was pleased because it rang true with my own personal experience of frustration with microscopic result reading.

 

I'm pointing out that it's difficult to evoke change or discussion when the manufacturer explicitly includes it in their instructions and many technologists (you're not alone AuntiS) have decades of experience using microscopes.

 

Now, my personal opinion noted, I remember a recent patient where a microscopic positive DAT led to an elution and found an anti-Jk(a) not in the plasma that could have theoretically harmed an elderly lady who subsequently received numerous transfusions. Should it have been observed as a weak positive instead? Hard to say.

 

edit: yessss, 500 posts!

Edited July 31, 201510 yr by goodchild

First we do still use a microscope though now mostly for DATs which we still do in tubes and read micro. We are looking at changing to Poly gel card but I think our first handful of samples done both ways are an interesting mish mash of results. While we are a hospital Blood Bank we also function as the primary reference Blood Bank for the system so I would be squeemish about not having a microscope. We see lots of cold antibodies at times and lots of rouleaux...I just want to SEE sometimes what I am dealing with. As we are now not reading antibody reactions micro I am pretty sure that a 1+ gel  is more comparable to a micro reaction than a macro tube reaction. Another issue I have come to find in our dalliance with a few years of Capture testing is that we lost a lot of skill at recognizing the affects of cold aby and rouleaux as they affected Capture testing. When you have SEEN a lot of colds and rouleaux you can SEE how they affect Capture and gels and tube testing. People with only Capture experience came to have unrealistic expectation of what you could expect from Capture testing...to me it was just another method at MY service...just a PART of the whole picture. I think the difference was having known blood banking through many years macro and micro is very helpful to me when resolving problems. IS micro a pain sometimes...TMI...yup but sometimes it gives me the knowledge I need to come to a conclusion.

We use microscope, if we suspect mixed field, rouleaux or weak/barely positive reactions seen macroscopically. We generally use gel for DAT, etc, so no need for microscope.

I have been following this topic because.... I have worked in TM for 14 years and have ALWAYS used a microscope to read negative reactions!  Four different hospital labs - all use a microscope.

 

I can't be the only one?

s

Well I did too - in the old days before gel - and when I was a lot lot lot younger!

I find checking tubes under the scope still quite useful and will just continue with it until I retire.  DATs, Fetal Screens (are SUPPOSED to be read under the scope) and weak reacting tube tests (especially when Capture is showing something and tube reactions are SO much weaker) are very useful, I find.  We do not read rare reagents under the scope as that can lead to mis-interpretation of the test results.  Rouleaus vs. agglutination is usually only detectable under a scope.  Not to mention (but I will anyway!) my eyes are not as sharp as they used to be and the concave mirror just doesn't always do enough for me.  Just like to see the reaction as MERRYPATH does.

 

Sorry, Malcolm!

I know of several reference labs that will use a microscope to look at negative reactions in tube testing and DAT testing. The facility I am now working at will only do it for DAT testing.

I have generalists who cannot/do not see weak macro reactions and/or who shake hard enough they kill weak macro reactions. I have not been able to reform them and I've been trying for a looooong time. (The younger ones I've trained do a much better job.) So, we use a microscope just to be sure everyone sees what they should be seeing.  Heavy Sigh!!! I do like to use a scope for patients who react weakly in solid phase when I'm doing tube testing to resolve IDs, plus DATs, rouleaux vs agglutination sometimes, and fetal screens of course. I'll confess to weaking eyesight as well (stupid bifocals!)