Any labs out there allow their techs to perform manual differential counts by high dry (50x) objective as opposed to oil immersion (100x) as a routine? An internet search would seem to indicate that some labs, by policy, do allow the use of 50x. Anyone willing to share their thoughts on this subject?

We have both 50 and 100x oil objectives on our scopes.   Techs use whatever they are comfortable with. No one that I know of would use a hi-dry here for a differential.

 

I usually only use 100x when looking at alot of cells, like in a bone marrow or cytospin of a chest fluid.

 

Scott

Same as Scott, 50 and 100x oil.  Techs count with whatever is most comfortable.

Deny

I've always believed that oil at 100x gives the best view of detail. We look at the expected and anticipate the unexpected. Since we live in an area here  with a higher incidence of Lymes and Anaplasma, we are always keyed to inclusions, which might not be seen at 50X. The rush to put out results, and I'm not being snarky, shouldn't preclude our giving it our best.

We us 50x OIL (the objective is an oil one), and go to 100x for very cellular blood smears, Bone Marrows and cytospins.

We use oil x50. Can't see the need to do a x100 unless you are specifically looking at the chromatin of the cells. For a basic diff x50 is plenty.

 

Also if you increase the magnification to x100 it makes it more difficult to see that you have drifted from the 'right' part of the film and could actually result in a false differential. I am forever telling trainees 'too thick' or 'too thin' when I am teaching them how to do an accurate diff.

50. If our lab was to use 100 we would all be spending twice the time doing diffs and much would be missed. Ever take a slide to the pathologist? They use a lower power than 50 to get the best overall view. Only go to 100 if there is something that needs inspection. If someone needs 100 to do a diff send them back to the student desk