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Preparing your sample

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What tissues should I trim off the globe?

Remove all tissues you don’t need us to evaluate.

If there is an intraocular tumor and you’re worried about surgical margins, we recommend you leave the extraocular tissues attached (and please tell us where the tumor is located). Marking lesions with sutures is nice if you like (and please explain the sutures). We endeavor to evaluate the optic nerve on all cases, so please leave it attached.

Here’s an example of a well-trimmed globe:

a well trimmed globe submerged in formalin a jar

How should I preserve my specimen?

All samples should be immersed in ten times their volume in 10% neutral buffered formalin 24-48 hours before mailing to us.

If you want to remove formalin for shipping, pack formalin-soaked gauze around the specimen for shipment.

Though Davidson’s solution provides beautiful preservation of the retina and lens, we actually prefer 10% neutral buffered formalin for the vast majority of routine samples. If you are sending research samples for which you’re exquisitely interested in the retina or lens, then please discuss with one of the pathologists whether Davidson’s is an ideal choice.

Should I poke a hole in the globe or inject formalin into it?

No! Please leave the globes intact and do not inject anything into them.

How should I send small samples, especially cornea?

We recommend putting small samples into cassettes and then placing them into formalin. We prefer the “mesh” cassettes with very small holes, but a regular cassette with a formalin-soaked blue sponge works well too. Make sure that the cassette fills with formalin and sinks when you place it into the container for good tissue fixation.

For conjunctival or corneal samples, we recommend laying them onto either fresh cucumber or a piece of paper or thin cardboard, allowing them to dry for ~ 5 minutes and then dropping them attached to their substrate into formalin. This helps prevent tissue curling, which helps with trimming and embedding the specimen.

How should I note where my lesion of interest is?

You can include a drawing on the submission form. You can explain with words (“dorsomedial iris” or “ventral ciliary body” etc). You can also put a suture into the episcleral tissue overlying a particular lesion – and then please explain why you’ve placed the suture. Remember that a mass or other lesion may be obvious to you clinically, but once the globe has been fixed, we may not be able to locate it through the cornea or locate it in the cornea (for ulcers etc).

If I have a sample from an exotic animal, should I do anything differently?

You may use the normal COPLOW submission form. Sample preservation is the same as tissue from a domestic animal. We may offer a discounted fee for samples from exotic animals – please contact the lab and speak to a pathologist.

What if I want to submit a clinical photograph?

Please email clinical photographs to the coplowfellow@vetmed.wisc.edu email account and include the patient’s name and owner’s last name.


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How should I package my sample?

Formalin jars with specimens should be put into a Ziploc bag. The submission form should be placed into a separate Ziploc bag to avoid formalin leaking onto the form. These items should then be surrounded by packing material (newspaper, brown paper, bubble wrap) in a cardboard box (not an envelope). Jars can be crushed in envelopes, resulting in destruction or loss of your precious specimen and leakage of formalin.

Below is a sad example of a jar that was mailed in an envelope and was broken during shipping. This can even happen with the padded FedEx or UPS envelopes – we really suggest a cardboard box!

ripped envelope besides a broken sample jar.

How can I prevent freezing of my sample during the frigid winter months?

Remember COPLOW is in Wisconsin and it is possible for samples to freeze during the winter months (November through March). Please add 10% of the jar’s volume of alcohol to the jar with formalin. Either 70% ethanol or 70% isopropyl alcohol will be fine. As an example, a formalin jar that contains 30 ml of formalin should have 3 ml of alcohol added. A 100 ml jar of formalin should have 10 ml of alcohol added.

Here is an example of a frozen globe. This induces terrible microscopic artifact that can preclude our ability to make proper diagnoses. You don’t want this to happen to your precious specimens!

Gross photo of a globe with freezing artifact

What shipping service can I use?

Any service you like! We recommend getting and keeping tracking numbers for each package you send. The cheapest option will likely not get the sample to us in a timely fashion, which will delay getting results.

Can I send samples from another country? Do I need to take them out of formalin first?

The legality and logistics of shipping formalin-fixed biological specimens varies by location and you should contact your local shipping agency/company to ask for the regulations and recommendations. We may need to help facilitate shipping specimens from our end – please call us or send an email (coplowfellow@vetmed.wisc.edu) to discuss. It’s best to allow the specimen to fix for 24-48 hours immersed in formalin and then send it with formalin-soaked gauze to avoid formalin leakage.


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How can I pay?

You can mail a check made out to “University of Wisconsin” with your sample & submission form. If you do not send a check, we will bill you. There is no need to set up a billing account before sending a submission. We can accept credit cards (American Express, Visa and Mastercard) for payment.

Who should I make the check out to?

please make checks payable to “University of Wisconsin”

How long will it take to get results

Once we receive the sample, our average turn-around time is about 3 days. Some cases require deeper sections of the blocks or special stains, which may take a few days longer. Please keep in mind your shipping method and estimated time for delivery when thinking about when to expect results from us. The tracking numbers can help you to estimate delivery date and thus when you should expect results.

If you have a case that you would like to be run “STAT,” please indicate that on the form and explain why you would like expedited results.

How much does it cost to get samples analyzed?

Small animal globe (dog, cat or smaller) with up to 3 additional periocular lesions (i.e. eyelid masses) = $110

Tissue (i.e. periocular tissue), up to three separate lesions = $100

Large animal globe (horse, cow, small ruminant, etc) with up to 3 additional periocular lesions = $120

2nd globe from the same animal = additional $20

Second opinion (slides / blocks sent from other diagnostic lab) = $25

Extra copy of slide for your own collection = $10