Blood Bank Testing Methods

[Noooooodles]

Hi all,

 

I'm still a relatively new blood banker and was wondering if you all would be willing to shed some light on the different methods of blood banking? We currently use solid phase but will be switching to gel next year.

 

I have some questions regarding each method but also wanted to see what seasoned techs have experienced with them. 

 

Solid-phase: 

1. Incubation @ 37 with potentiator 
2. Wash
3. AHG
4. Read

 

Pros: Sensitive

Cons: 

Question: Won't pick up on clinically insignificant cold autos because of less exposure to cold temperature during the process? Or is it due to something else? Good to use with insignificant cold auto if you don't want to pick them up on screen?

 

______

 

Gel: 

1. Incubation @ 37 on top chamber, with potentiator?
2. No washing
3. Spinning down through the matrix containing AHG

 

Pros: Very sensitive 

Cons: Will pick up insignificant colds due to the chamber temperature and matrix can catch IgM? Rouleaux

Notes: IgM remains as there's no washing

 

_______

 

LISS Tube (skipping IS phase): 

1. Incubation at 37 with LISS
2. Reading (for strong IgM or IgG)
3. Wash (removing unbound Abs)
4. Add AHG
5. Read (for IgG)

 

Pros: Not too sensitive, not too weak

Cons: Won't pick up weak antibodies

Question: Won't pick up insignificant warm because LISS isn't strong enough? (Such as weak warm auto) Good to use when not wanting to pick up warm auto on screen?

 

________

 

PEG Tube:

1. Read at IS (for IgM)
2. Add PEG, incubate at 37 (30min inc. might pick up insignificant Abs?)
3. Wash
4. Add AHG
5. Read (for IgG)

 

Pros: Strong than LISS

Cons:

 

Please feel free to share any thoughts or experience.

[John C. Staley]

I'm curious, what is the motivation for moving from Solid Phase to Gel?

[Noooooodles]

On 12/24/2023 at 6:12 AM, John C. Staley said:

I'm curious, what is the motivation for moving from Solid Phase to Gel?

It's cause our contract is coming up and we can't find another solid phase instrument for our sample volume. Much more choices with gel instruments. 

[jshepherd]

On 12/23/2023 at 9:06 PM, Noooooodles said:

 

 

Solid-phase: 

1. Incubation @ 37 with potentiator 
2. Wash
3. AHG
4. Read

 

Pros: Very Sensitive

Cons: Will pick up insignificant interference, like proteins, and can cause false positives. 

Question: Won't pick up on clinically insignificant cold autos because of less exposure to cold temperature during the process? Or is it due to something else? Good to use with insignificant cold auto if you don't want to pick them up on screen? True - but the colds that are missed are insignificant. 

 

______

 

Gel: 

1. Incubation @ 37 on top chamber, with potentiator?
2. No washing
3. Spinning down through the matrix containing AHG

 

Pros: Very sensitive 

Cons: Will pick up insignificant colds due to the chamber temperature and matrix can catch IgM? Rouleaux Has a history of missing certain antibodies (E and Jka) even when they are not weak. If you plan to do AHG XM with Gel as well, you'll still need to do the IS phase in tube. 

Notes: IgM remains as there's no washing

 

_______

 

LISS Tube (skipping IS phase): 

1. Incubation at 37 with LISS
2. Reading (for strong IgM or IgG)
3. Wash (removing unbound Abs)
4. Add AHG
5. Read (for IgG)

 

Pros: Not too sensitive, not too weak 

Cons: Won't pick up weak antibodies

Question: Won't pick up insignificant warm because LISS isn't strong enough? (Such as weak warm auto) Good to use when not wanting to pick up warm auto on screen? Correct, we will try a LISS or Saline screen when there is a weak warm auto and we know there are no underlying allos. 

 

________

 

PEG Tube:

1. Read at IS (for IgM)
2. Add PEG, incubate at 37 (30min inc. might pick up insignificant Abs?)
3. Wash
4. Add AHG
5. Read (for IgG)

 

Pros: Strong than LISS, gold standard in my institution

Cons: not good for patients with warm autos

 

Please feel free to share any thoughts or experience.

Just a few nuggets I left in BOLD above. We use solid phase here, and back up to tube (we have PEG and LISS). I personally prefer solid phase, but each method has it's pros and cons. This is why you need more than one method to utilize. Good luck! 

[Noooooodles]

On 12/26/2023 at 7:01 AM, jshepherd said:

Just a few nuggets I left in BOLD above. We use solid phase here, and back up to tube (we have PEG and LISS). I personally prefer solid phase, but each method has it's pros and cons. This is why you need more than one method to utilize. Good luck! 

Thanks for the input! Really appreciate it