Fecal Float Questions

[Folly's place]

I've never looked for centrifuges to buy, only used the $$$ ones at work. They have more functions than only doing fecals, so it makes sense that a cheaper model would do for running fecals.
Do them in a dedicated space, NEVER in the kitchen!!! OSHA wants them done under an externally vented hood for a reason.
Mary

 

[jolenesdad]

Thank you @Sue Gremlin for sharing your expertise!!! Behind in the thread but I will catch up with comments.

wanted to drop in and ask.... what are the requirements for a centrifuge for fecals? I see multiple options and I can’t tell what’s best. Does it need to fit a certain size test tube? Fixed angle, vertical or swinging? I’m enjoying practicing with the McMasters float techniques but would like to build towards being super accurate.

 

[Sue Gremlin]

Thank you @Sue Gremlin for sharing your expertise!!! Behind in the thread but I will catch up with comments.

wanted to drop in and ask.... what are the requirements for a centrifuge for fecals? I see multiple options and I can’t tell what’s best. Does it need to fit a certain size test tube? Fixed angle, vertical or swinging? I’m enjoying practicing with the McMasters float techniques but would like to build towards being super accurate.

What are you doing McMaster tests on? Chicken feces? I would not say I'd recommend that since it dilutes the fecal sample and won't be sensitive enough to detect infections in a lot of cases.
You can use a fixed-angle or swinging bucket centrifuge to do fecals. The swinging variety is more suitable for fecals since you can put your tube in, fill to the top and cap with a cover slip, which will go along for the ride and do just fine. You just need to lift the coverslip and read your slide. They happen to be more expensive so harder to find. I wish I had one!
I have a few fixed-angle centrifuges. You will have to leave about an inch of space in the tube, spin your sample for 5 min, remove the tube and set upright, fill to the top with float solution, cover with cover slip and wait another 10 min before you lift it and read the slide.
Mine have buckets that are suitable to hold a 15 mL tube, which is a good size for a standard cover slip.

 

[Sue Gremlin]

I've never looked for centrifuges to buy, only used the $$$ ones at work. They have more functions than only doing fecals, so it makes sense that a cheaper model would do for running fecals.
Do them in a dedicated space, NEVER in the kitchen!!! OSHA wants them done under an externally vented hood for a reason.
Mary

My concern is the physical hazard. A heavy rotor spinning at 15000 RPM has a LOT of energy. If it's unbalanced, it can crash and send the rotor right through a concrete wall. Centrifuges can be really dangerous!

 

[jolenesdad]

What are you doing McMaster tests on? Chicken feces? I would not say I'd recommend that since it dilutes the fecal sample and won't be sensitive enough to detect infections in a lot of cases.
You can use a fixed-angle or swinging bucket centrifuge to do fecals. The swinging variety is more suitable for fecals since you can put your tube in, fill to the top and cap with a cover slip, which will go along for the ride and do just fine. You just need to lift the coverslip and read your slide. They happen to be more expensive so harder to find. I wish I had one!
I have a few fixed-angle centrifuges. You will have to leave about an inch of space in the tube, spin your sample for 5 min, remove the tube and set upright, fill to the top with float solution, cover with cover slip and wait another 10 min before you lift it and read the slide.
Mine have buckets that are suitable to hold a 15 mL tube, which is a good size for a standard cover slip.

McMasters for the horses. I also did one official McMasters on my heavily burdened chicken to try and get an actual count.

I’ve been using the McMasters slides to help me learn how to focus and move the slide around the microscope, but not diluting it all the way with the chicken fecals to get a chance to see. I had been doing McMasters at 25/gram sensitivity, but coming up clear on a few chickens that I did not think were really clear.

@aart has been pushing me to a centrifuge since the beginning but I wanted to make sure I even knew how to focus a microscope!

So, the less expensive centrifuges that you have to fill after and then coverslip are good enough? I hope so cause most of the swinging style are over a thousand bucks!

 

[Isaac 0]

I got an old fixed angle rotor centrifuge from a friend, and that's what I've been using. I fill the tube up about 1cm below from the tip, centrifuge it for five minutes, take it our form the inverted meniscus, and so forth.

This is my model.

https://www.ebay.com/i/363022185497?rt=nc&_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=2&asc=225074&meid=d220bea56dc94955bb5237b6429104a7&pid=100677&rk=15&rkt=30&mehot=none&sd=143560506183&itm=363022185497&pmt=0&noa=1&pg=2386202&algv=DefaultOrganic&brand=IEC

Of course, there are lots of better ones out there too. This one sounds like a train engine when running, lol.

Once you have all the fecal float supplies, you can really start getting into other stuff too,(need stains!) I've been doing/trying to do peripheral blood smears, and gram stains, etc.

 

[KsKingBee]

This centrifuge works great and only cost $75. and comes with tubes. You do need to counterbalance your tube with another tube opposite the one you are using with plain water.

 

[EggSighted4Life]

In fact, you may not know, but here there is hugely strong public opposition to the UK doing a trade deal with the US to import chlorinated chicken meat. I have no idea why the US chlorinates meat but can make a few guesses.

I was shocked when I looked at processing facilities to consider having my birds done there to discover they would coat the inside and out of the carcass with chlorine. It's a deal breaker for me so I harvest my own birds.. and surprisingly they stay fresh with no smell or slimy feeling for 3+ whole weeks! The reason they do it is because they are processing tons of birds all from different sources and cross contamination is a consideration. I also imagine machine processing does more ripping and tearing possibly busting guts open or other sorts of contamination. Dare I say.. our justice system is a bit skewed and lawsuits require companies to protect themselves in that way... but as you stated, profit driven, demand for low cost. blah blah, etc... it's complicated. Most folks here in the US do not truly understand or comprehend the cost of farming. Now that I KNOW what I'm paying for.. I understand why milk and meat are so high cost and the value of what I'm getting!

At home all the birds are from my place only. I harvest by hand one bird at a time. They never float in a pool of bloody poo water with other dead birds. Thankful for my lot in life! Harvesting my own heritage birds and eggs cost me not less than double supermarket price. A tough pill to swallow, not doable for many.

Coccidia, in a healthy chicken, probably come and go, so they don't shed oocysts consistently. It could also be that your chickens are not infected, which seems unlikely, but still possible, theoretically. Third, it could be your flotation technique: Using enough feces? Is your solution dense enough? Are you looking with the correct lens?

I know my birds (or property) have coccidia because I have had outbreaks during crowding in the past.

My floats thus far have been group floats, done at the vets office, with a centrifuge (I asked). I can only presume they are using proper technique.

Thanks guys for sharing your thoughts!

 

[Folly's place]

Mis-handling a centrifuge is very dangerous, totally true! And playing in poo without gloves, etc, isn't smart either. Why I've been happy to send it all out.
Mary

 

[Isaac 0]

Mis-handling a centrifuge is very dangerous, totally true! And playing in poo without gloves, etc, isn't smart either. Why I've been happy to send it all out.
Mary

This.

It seems people are too excited to actually do a float, and don't look into how to properly use the equipment involved with doing one(me).

First time I used a centrifuge, I didn't put a balance tube in, and It was like an earthquake was going on inside the house.