Difference in droppers?

[blooddiva]

Has anyone every studied whether the Biotest dropper produces larger drops, and thus you get less tests per vial?

[Lcsmrz]

Someone told me a story during an assessment about Biotest reagents, when one ran out before the other, even though they are used in tandem. He found that one vial's dropper had slightly larger drops, causing it to run out before its companion.

Sorry, don't remember any more details than that. At my age, I'm lucky that I remembered the event!

[blooddiva]

Thank you, I haven't looked head to head, but I swear we are going through more reagents. thus we are not fully realizing the price savings versus Immucor.

[Eagle Eye]

If you have immucor vial, why don't you measure how many drops for each vendor and compare???

[Fluffy agglutinates]

We're not allowed to use the dropper! We use a pipette to give a precise amount e.g. 50ul for a 'drop'

I think it's just as likely to be the user as the dropper - it depends on angles, amount of 'squeeze'! etc.

[Malcolm Needs ☆]

We're not allowed to use the dropper! We use a pipette to give a precise amount e.g. 50ul for a 'drop'

I think it's just as likely to be the user as the dropper - it depends on angles, amount of 'squeeze'! etc.

I totally agree.

[BBK710]

Thank you, I haven't looked head to head, but I swear we are going through more reagents. thus we are not fully realizing the price savings versus Immucor.

We are evaluating the Biotest reagents so I was very interested in this post. I just compared Biotest antisera to Ortho antisera. Twenty drops of Ortho antisera was 1.1 ml. and twenty drops of Biotest was 1.4 ml. Granted this was not done to strict standards but it seems pretty obvious that you will get fewer tests per vial from Biotest which probably off sets their lower prices. I am going to mention this to my rep and see what she has to say.

Edited April 2, 2010 by BBK710
spelling

[Dr. Pepper]

I just bought vials of anti-e, -M and -N from Biotest. I haven't calibrated the droppers yet; I was more concerned that the anti-M expired last February! The other two barely have 6 months before outdating. We're a smaller lab and these aren't your heavy hitters like anti-K or -E. I'm not impressed at all with this.

[adiescast]

That is a bad problem. Even bigger labs don't use the antisera that fast (unless they happen to do mass screening, but I don't know how common that is...).

[galvania]

Droppers for antisera and cells are not standardised - and don't claim to be. It is more than possible to have 10 bottles from the SAME lot of a reagent and each bottle dropper to dispense a different volume. People using droppers are not standardised either - so 10 different people using the same dropper can dispense 10 different volumes. If you want standarsiation you have to use a specific quantity, measured in ul rather than in drops

[JEMarti]

There is a difference between manufacturers in how their droppers dispense.

The first issue is the angle the tech holds the dropper. I have tested the number of drops dispensed from various vials of Ortho, Immucor/Gamma and Biotest antigen typing antisera. All three show a significant difference in the number of drops dispensed. Ortho and Biotest run approximately 40% fewer drops if the tech holds the dropper at an angle. Immucor Gamma runs about a 20% difference. The issue with Biotest reagents is that they contain only 2ml in many of their products so it feels like you are blowing through reagents.

The second issue is whether the tech follows the IFU. Most IFU's call for one drop of sera with one drop of cell suspension. Techs trained back in the day before many of the newer, stronger reacting clones often will drop 2 drops instead of one. Dropping 2 drops more than negates the advantage of holding the dropper upright.

None of the manufacturers has a dropper that is right on 50ul. They are all slightly more than that. The closest I have seen is consistently in the mid 90 drops from a 5 ml vial. Regardless of your supplier you can probably make bigger gains in cost savings by simply working to reinforce good technique amongst your staff.

[dcubed]

I know this is fairly obvious, but some of the Biotest anti sera only contain 2 ml per vial. Is this part of the problem?