Hello there,

It has been some while since last time I was here.

We're planning to validate a new Kleihauer Betke staining method as our current one does not work well (especially with CAP samples) and trying to determine # of samples required for this validation. We couldn't find any requirement/standard to specify the # sample needed to fulfill the purpose of validation. Could anyone please provide some related information? Thank you for your help.

Clarest

 

 

Per CLSI, the minimum number is 20 sample.  Make sure the Samples you select are fairly distributed in range from negative to large bleed.

 

In addition to the 20 samples, if you are not able to find weak positives, you can make your own weak positives. Just Google it.

Thank you very much cheru26 and scott for your help.

AABB and CAP do not have a minimum sample requirement.  In your validation document you should determine how many samples you need to run.  Just as an aside, if you could find a Thal minor patient they provide an interesting specimen as they have a persistence of fetal hgb. 

On 11/21/2016 at 7:14 AM, David Saikin said:

AABB and CAP do not have a minimum sample requirement.  In your validation document you should determine how many samples you need to run.  Just as an aside, if you could find a Thal minor patient they provide an interesting specimen as they have a persistence of fetal hgb. 

Hi David,

I was thinking something similar such like a sample from a patient with an elevated hgb F. Thank you for your suggestion. We're planning to manually make 14 positive samples (as we do not have that many positive samples routinely) with different percentages (0.1% to 10%) of positivity, plus 6 negative samples to make a total of 20 samples. The problem is to define the acceptable range of each positive sample after being read. For example, I make up a positive sample with about 2% fetal cells. After the technologist reads the slide, what is the acceptable range to prove that the staining method is valid. We do not have a flow cytometry to check for us. I notice that CAP usually gives a wide acceptable range for KB proficiency testing. I am wondering if anyone could give some suggestions or share a validation protocol of KB testing method. Thank you in advance.

Clarest

Hi,

Could anybody answer my above question regarding how to define the acceptable range after the validation slides are read? I really appreciate your help.

Clares