It is a good idea to perform the dissection using the duodenal "C" as the reference. Briefly, when you start, you start with spleen and then remove most of the adhesions to the surrounding tissues and then proceed to locate duodenal C and finely dissect making sure you are not leaving out any pancreatic tissue. Remember to store in saline and remove any floating fat tissue.

In cases of survival surgery of rodents where the target was to perform total pancreatectomy, it was exceedingly difficult to reach the 100% removal of the organ. The best I achieved was about 95% pancreatectomy. The difficulty is due to the fact that the purpose was to have the animals survive.

Yes, the pancreas in rodents is "intertwined" between organs - its tail begins from the spleen and it's attached from stomach through duodenum and beyond. In case where the removal of pancreas is a terminal procedure, with care it can be completely removed and fairly quickly. It may take a few attempts to learn the subtle difference in appearance between the pancreas, fat and lymphatic tissue but once one sees the difference in color, it becomes easy. 

If you happen to be interested in isolating mRNA from pancreas, I would strongly recommend modifications to method outlined above that allow to speed the process. If interested in details, let me know.

Pancreatic tissue is adhereing to the spleen and going towards the duodenum. If you lift the spleenslightly, you can visually see the tissue hanging. Slowly remove the adjoining tissue and move towards the duodenum, always holding the pancreas.

What do you plan to do with the organ once you have it out? Are you removing other organs as well? If so, are you getting the pancreas first? The pancreas will begin to autodigest as soon as the animal is dead or the blood supply to the pancreas is stopped. If you need pancreas, you need to get that one first!

If you want the organ for histology, I would advise against holding the pancreas with your instruments, as you will damage the tissue and will not get very good slides.

Nude mice are particularly difficult due to their small size. If possible, try on a larger mouse or even a rat in order to familiarize yourself with the anatomy. I prefer to have the mouse head towards me, open the abdominal cavity, grasp the liver with gauze and flip it towards the mouse head. Now, push the intestines to your left and you should be able to clearly see both the gall bladder and the bile duct as it enters the pancreas and you can also see where it exits the pancreas and enters the small intestine. Note this area, because the bile duct is tougher than the rest of the connective tissue that holds the pancreas in place. You can damage the pancreas if you pull when you should cut.

If I am not isolating pancreatic islets, so the pancreas is not inflated, I usually begin at the stomach, gently separating the connective tissue from the stomach, following towards the small intestine. Carefully separate the pancreas from the duodenum and then follow along the length of the small intestine. At some point, you will get to the area where it is attached both to small and large intestine. At that point, I loosen connective tissue from the caudal end of the large intestine. Ther is a fatty bunch of tissue that can be cut, but be careful, looking at the color and texture of the tissue to ensure that you are not cutting pancreas. At this point, I grasp the bile duct and gently lift, cutting and  separating any attachments underneath and following to the spleen. Trim the pancreas away from the spleen and voila! If you need to trim fat off, do so in a petri dish of saline. I can do it in less time than it took me to type this up, but that comes with 20 years of practice!

Do use magnification! It really helps a lot. I like the wearable magnifiers better than trying to use a dissecting scope. Also, if you can bleed the mouse out, that is nice, because not only does blood make it harder to see what you are doing, it kind of stains the fat and makes it just that much more difficult to tell the fat from the pancreas.

Hey Erica,we are doing the same .generally pancreatic tissue is adhering  to the spleen so. first you find the spleen  and   so the  pancreas is just attached to that spleen you just  dissect the surrounding tissue  AND MOVE TOWARDS THE DUODENUM AND REMOVE CAREFULLY.

Hi All, Thank you so much for all your valuable advice, it helps a lot.

I need it for mRNA isolation, as well as at a later stage for immunohistochemistry and BioImaging as well.

I am more interested in the GLP1 receptors present in the Pancreas, we are trying to image it using a peptide specific for it, but for some reason after 4 hours it gets eliminated.

If anyone could help me out with this issue as well I would really appreciate it.

Thank you in advance again.

Erica, Elizabeth has given you a detailed description how to carefully remove the pancreas.

Since you are going to use the pancreas for RNA, taking minimum time is essential and that will come with practice.

A few things that may help:

1. Avoid bleeding in the abdominal area which will obliterate the distinction between the pancreas and other soft tissues around it with similar appearance. To achieve this, open the abdominal cavity (I use the opposite orientation compared to Elizabeth where the head of the animal is away from me) by making a large mid-line incision without puncturing the diaphragm, scoop the intestines to the right of the mouse (belly-side up, left hand side of the operator), push the stomach in the opposite direction so you can clearly see areas of pancreatic attachments, extend the midline cut into the thoracic cavity, and cut the aorta or the heart so all blood is contained within the thoracic cavity. 

2. For RNA work, I do not waste time by soaking or washing the pancreas in saline etc. I simply pick the spleen (an organ that probably does not interest you) and lift the pancreas with it, follow it to the stomach, duodenal loop and intestine while quickly but carefully cutting it. Place it in a petri dish with a weighing paper, which serves to save time in removing unwanted tissue which you may have brought along with the pancreas by not letting the tissue slide around all over the petri dish. The last thing that gets removed is the spleen, which conveniently keeps you oriented throughout the procedure with the layout of the pancreas.

If you are going to use the same pancreas for RNA and other biochemical tests, split it in two portions but ensure that both halves get about equal portions of the entire organ (islets from head and tail have different cellular makeup). Place one half for RNA on a prelabeled Al foil, fold it and dunk it into liquid nitrogen and process the other half according to your protocol.

Once you become a little comfortable, make the first cut end to end in one quick movement - with sharp scissors, one doesn't even need to literally cut. A little nick and then the rest goes like the way fabric is cut along the width without moving scissors. This entire procedure (post-deep anesthesia or euthanasia to procuring the organ) takes only about 1 min, may be 2min on a very slow day. 

About GLP1 receptor lasting "only" 4hr in isolated pancreas, given that pancreas produces large quantities of digestive enzymes capable of degrading all cellular components, I'd say that 4hrs is quite good!  ;) 

If you elaborate on exactly what how you are processing your pancreas to image GLP1r, you may get some useful suggestions.

Good advice, Tausif!

It is true that people have preferences as to the orientation of the mouse, so find what works best for you. If you do exsanguinate, do this by cardiac puncture to avoid blood in the body cavity.

When you look for GLP-1 receptor, is this in fixed tissue? If not, maybe fixation prior to imaging would help. Look up research from Dr. Jens Holst's , or Dr. Daniel Drucker's lab. They are both top notch researchers with interest in GLP-1. I included a link to Dr. Drucker's website - it is very nicely done and is my go-to for anything glucagon related.

If your institution has a issue sharing program, you may be able to get some practice mice that are slated for euthanasia to practice on. Retired breeders of most any strain may be larger than your nudes and a little easier to practice on.

Good luck!

http://glucagon.com/glp1receptor.html

The below image attached with this post is what I am getting.

When we dissect the organs, we are not sure whether it is the pancreas that is fluorescing or the pancreas intertwined with the intestine or the intestine itself.

Can anyone help me out with regard to the above image?

Thanks!

Erika, given the limited information you have provided about your experimental design and more to the point, the actual goal of your experiment, it may be difficult for others to identify what is lighting up in your 2-D images. On the basis of information about tissue distribution of GLP-1 receptors, which has been available for decades, one can surmise that in your image you could be seeing both the duodenum and the pancreas. Lungs, liver, and kidneys all are supposed to have GLP-1R but you are not seeing them.

Have you done any specific treatment which may have upregulated the receptors in one organ versus the other?

On a negative note, it may be simple non-specific retention of your antibody in the spleen and nothing to do with specific binding to GLP-1 receptors... just something to think of!

Colocalization experiments employing well established cell surface markers for specific organs may be quite useful.

Hello,

Harvesting the entire pancreas from a mouse for experimental purposes requires a precise and careful approach, due to the organ's intricate location and delicate nature. Here is a step-by-step guide to ensure a complete and successful extraction:

By following these steps with care and precision, you can successfully harvest the entire pancreas from a mouse, ensuring the integrity and utility of the tissue for your research purposes.

Take a look at this protocol list; it could assist in understanding and solving the problem.