DrBaboon
10-25-05, 11:17
I thought I'd mention some things related to hemacytometer (hemocytometer) cell counts.
Here's a picture from a vendor to illustrate the items:
http://www.hemcindia.com/gifs3/60-102-haemacytometer.jpg
As best I can tell, we've mainly had information on the actual "grid" that is the hemacytometer itself. FWIW - simply taking a look on eBay turns up examples where you are only getting the hemacytometer.
This is not so much a special slide, as it is a chamber. The grid/slide/hemacytometer itself needs to have coverslip put on that bridges the supports built into the hemacytometer. Placing the coverslip into position is what completes the chamber.
You also need pipettes appropriate to what you are measuring - there is a RBC pipette and a WBC pipette. They typically have a piece of material in the bulge in the middle of the pipette. No surprise, the piece of material is either "red" or "white."
The same vendor has a nice picture of the pipettes:
http://www.hemcindia.com/gifs3/60-104-blood-diluting-pipet.jpg
I'm sure that some people have bought these new, but other people have bought them used. What concerns me is the whole concept of mouth pipetting. Basically, it amounts to sucking on a straw that is dipped in someone's blood. That's bad enough if you've bought new pipettes and are doing cell counts for your family. You can see where I'm going with this - especially on used pipettes.
Every picture I've come across on the web which shows the pipettes, has the same kind of mouthpiece and tubing with the pipette.
A regular eyedropper type bulb is a little clumsy and touchy for use on these pipettes.
I've seen some people use the pipette bulbs that have 3 valves in them. That seems workable, but keep in mind that the bulb capacity is really big compared to the tiny volumes in these pipettes.
What do I have in my bag of tricks?
I've had this gizmo for 20 years or so, and don't recall it's exact name, so I'll describe it. It's a short metal cyllinder, with a knurled plunger that screws into the top of the cyllinder. There is a nipple on the bottom of the cyllinder, and a short piece of rubber tubing on the nipple. There is an O ring on the bottom of the screw-in plunger.
You fit this on the top of the pipette, and gently unscrew the plunger while holding the pipette tip in the blood or in the appropriate diluting solution. You can also dispense (or completely blow out) from the pipette by slowly screwing the plunger into the cyllinder.
I'm sure I bought this from some supply house. I've done a little looking around, but haven't found one on the web yet.
It would be an easy enough item to fabricate if you could not find one for sale.
Maybe I'll think of the correct name of the item, or perhaps someone else will mention it, and that might make it easier to look for one on-line.
Bottom line: I hope to discourage people from mouth pipetting, even though it's the traditional thing to do.
My other point was to remind folks that they need to have the whole kit if they are going to do cell counts via hemacytometer. Dedicated hemacytometer coverslips are larger, thicker and stronger than regular coverslips. They are meant to be cleaned and re-used, but they still break once in a while. I don't believe it's going to work well to use regular coverslips. Having a number of replacement hemacytometer coverslips is a good idea.
Of course, you can manually mix blood in the pipettes.
Since I used to do this in the office, I have several WBC pipettes (I find it more helpful to do hematocrit or hemoglobin instead of a RBC count) - so I can have more than one patient's blood being worked on at a time.
I also went one step further and got a small machine that has a rubber rack for the filled pipettes, and vibrates them for mixing. Yes - of course - that means electricity, and that may or may not be available.
Anyhow - I thought it might help people consider this as they plan and make any purchases.
Here's a picture from a vendor to illustrate the items:
http://www.hemcindia.com/gifs3/60-102-haemacytometer.jpg
As best I can tell, we've mainly had information on the actual "grid" that is the hemacytometer itself. FWIW - simply taking a look on eBay turns up examples where you are only getting the hemacytometer.
This is not so much a special slide, as it is a chamber. The grid/slide/hemacytometer itself needs to have coverslip put on that bridges the supports built into the hemacytometer. Placing the coverslip into position is what completes the chamber.
You also need pipettes appropriate to what you are measuring - there is a RBC pipette and a WBC pipette. They typically have a piece of material in the bulge in the middle of the pipette. No surprise, the piece of material is either "red" or "white."
The same vendor has a nice picture of the pipettes:
http://www.hemcindia.com/gifs3/60-104-blood-diluting-pipet.jpg
I'm sure that some people have bought these new, but other people have bought them used. What concerns me is the whole concept of mouth pipetting. Basically, it amounts to sucking on a straw that is dipped in someone's blood. That's bad enough if you've bought new pipettes and are doing cell counts for your family. You can see where I'm going with this - especially on used pipettes.
Every picture I've come across on the web which shows the pipettes, has the same kind of mouthpiece and tubing with the pipette.
A regular eyedropper type bulb is a little clumsy and touchy for use on these pipettes.
I've seen some people use the pipette bulbs that have 3 valves in them. That seems workable, but keep in mind that the bulb capacity is really big compared to the tiny volumes in these pipettes.
What do I have in my bag of tricks?
I've had this gizmo for 20 years or so, and don't recall it's exact name, so I'll describe it. It's a short metal cyllinder, with a knurled plunger that screws into the top of the cyllinder. There is a nipple on the bottom of the cyllinder, and a short piece of rubber tubing on the nipple. There is an O ring on the bottom of the screw-in plunger.
You fit this on the top of the pipette, and gently unscrew the plunger while holding the pipette tip in the blood or in the appropriate diluting solution. You can also dispense (or completely blow out) from the pipette by slowly screwing the plunger into the cyllinder.
I'm sure I bought this from some supply house. I've done a little looking around, but haven't found one on the web yet.
It would be an easy enough item to fabricate if you could not find one for sale.
Maybe I'll think of the correct name of the item, or perhaps someone else will mention it, and that might make it easier to look for one on-line.
Bottom line: I hope to discourage people from mouth pipetting, even though it's the traditional thing to do.
My other point was to remind folks that they need to have the whole kit if they are going to do cell counts via hemacytometer. Dedicated hemacytometer coverslips are larger, thicker and stronger than regular coverslips. They are meant to be cleaned and re-used, but they still break once in a while. I don't believe it's going to work well to use regular coverslips. Having a number of replacement hemacytometer coverslips is a good idea.
Of course, you can manually mix blood in the pipettes.
Since I used to do this in the office, I have several WBC pipettes (I find it more helpful to do hematocrit or hemoglobin instead of a RBC count) - so I can have more than one patient's blood being worked on at a time.
I also went one step further and got a small machine that has a rubber rack for the filled pipettes, and vibrates them for mixing. Yes - of course - that means electricity, and that may or may not be available.
Anyhow - I thought it might help people consider this as they plan and make any purchases.