B.Bullock

Apologies for not replying to this very old post. I just discovered it. Quotient makes a reagent red cell product that is very similar to the r-set that Gamma made many, many years ago. The product is Expanded Rh Negative Antibody Screen product code # Z464U . It is composed of 3 Rh negative cells that form a robust antibody screen (except for D) and a 4th cell that is an Ro to confirm the passive Anti-D from the Rh Immune Globulin. Package inserts and antigen profiles are available and can be downloaded from Quotient's website, no special access codes required. https://quotientbd.com/us/products/alba-by-quotient/red-blood-cells/

if your laboratory is CLIA licensed, as most labs in the US are, you are required to follow the CLIA regulations. The CFR requires a negative control. It is found in the CLIA regulations 42 CFR 493.1256 Standard: Control Procedures. 42 CFR 493.1256 (c)(2) For each test system, perform control procedures using the number and frequency specified by the manufacturer or established by the laboratory when they meet or exceed the requirements in paragraph (d)(3) of this section. (d)(3) At least once each day patient specimens are assayed or examined perform the following for - (i) Each quantitative procedure, include two control materials of different concentrations; (ii) Each qualitative procedure, include a negative and positive control material. Further down in that section, there are requirements to test controls before resuming patient testing when a complete change of reagents is introduced... to rotate control material testing among all operators who perform the test, and to test control materials in the same manner as patient specimens.

Until I studied the subject, I too did not think too much about the saline I used in my lab. But simple, everyday items like saline can have a huge effect on blood bank testing. The type of saline is extremely important. There is a post that I wrote located on the Quotient website. Here is the link http://www.quotientbd.com/us/from-the-q/why-is-saline-so-important-is-one-type-of-saline-better-than-another A few articles are referenced in the post, and make interesting reading.

If the questions arose from my note, I was referring to a study of expired reagent red cells. The study looked at cells out to three months post expiration. In-date cells are studied by reagent manufacturers extensively.

There was another study that looked at antigen stability of commercially-prepared panels, with the goal of validating the use of expired panel red cells in antibody identification tests. It was performed by a large group, and was published as an abstract in Transfusion. Particulars are Hamilton, JR, et.al. Validation of Expired Red Cells for Use in Antibody Identification Tube Tests. Transfusion 2004; 44: S60-040C.

I would bet on a E mosaic. The micro array won't pick up single nucleotide changes (and missing pieces or parts) in the RhCE allele. Particularly since he seems to like units that are negative for E along with his other favorite flavors. To prove it of course you would need to have the gene sequenced - somewhere like NY Blood Center. You didn't mention his race. We seemed to see more RhD and RhCE mosaics in our African-American patients.

David, Mabel is correct. Quotient is interested in performing further research on patient or donor samples which have been tested using our Partial D Kit, but give patterns that differ from the patterns on the Partal D Kit insert. We know that those patients are infrequent, but they are out there, and we would like to test them further so that we can expand the known pattern insert. I think you said that some of your patients work at your hospital and may be available? The additional testing we would perform would be at no cost to you, since we are currently doing this research. Please contact me using the Quotient Technical Service line 888-228-1990.

Liz, Think about it. The facility sent segments from units that looked compatible with antibody negative serum. Of course they looked compatible! They asked bbanker2 to type these specific segments for Jka, as if the compatibility somehow made them more likely to be Jk(a-). If bbanker 2 tested those specific units, he would have no better chance than testing random units. Jeanne's right.

We are all familiar with human anti-M antibodies that react better at a lower pH, and human derived reagents may also react better at a lower pH, but this Quotient Anti-M is a murine monoclonal IgG. I am sure you are aware that monoclonals are not always logical in the way they react. This monoclonal reacts best at a pH of 8.5, and is extremely sensitive to pH. The buffers in saline (or alsevers), which work well to stabilize the saline pH, change (buffer) the pH of the test. The monoclonal anti-M does not like the adjusted environment. Luckily all of our other monoclonals do not have this requirement. They are not so finicky.

Please let me clear this up. As Technical Director for Quotient, i can definitively tell you that the ONLY Quotient anti-sera that requires unbuffered saline is the Anti-M. Package inserts from all other Quotient anti-sera list isotonic saline.