I identified some cells of interest and would like to see whether they are found more in endomysium or in perimysium connective tissues.

Julie, you know about the anatomical/histological term "a) endo- and b) perimysium" as

a) location within a bundle of solitary muscle fibers (= usually a muscle fascicle) and b) location outside (= in between ="inter"  - normally well separated -  organized single muscle fiber bundles = muscle fascicles? 

So if you can't use different collagen types for discrimination (by FLUOR-MICR) of endo- and/or perimysial spaces you either should be able to locate easily and clearly muscle fibre bundles=fascicles (the space in between those fascicles usually is termed perimysium)  and therefore the really narrow spaces left in between fascicles and solitary small muscle fibers represents endomysial space. If you cannot discriminate rather easily these two spaces due to your specimens you have to find a suited fluorescent staining for (all) the muscle fibres you are observing.

Best wishes and regards, Wolfgang

Thank you all for you input.

I think I'll have to do with the pattern obtained after staining of muscle fibres.

I also learnt that in healthy young humans, collagen XII and XIV can be specifically stained in perimysium and not endomysium. But as soon as there is hard physical activity, ageing or injuries involved, endomysium is also stained. In my case it's not possible to use these types of collagen but it may help someone else.

Best, Julie

Dear Julie,

As Wolfgang Muss pointed: just stay in the correct microanatomy/histology terms- endomysium: the connective tissue surrounding a small bundle of skeletal muscle simplasts (fibres) i.e. fascicle; perimysium: the sheet of connective tissue surrounding several fascicles. Normally the perimysium is thicker (more collagen deposited), than the endomysium. Cross section through the muscle will help you to identify and locate both structures easily. 

Best,

Ivan

Honestly, I think this is a lost cause.  First of all, the two collagen groups are intimately intertwined so that there is probably no functional distinction.  Second, there are no collagen types that have been uniquely associated with one or the other.  These are "convenience" terms for us and probably have no true biochemical distinction.  The only thing that we have found that is unique about the perimysium is the the large collagen bundles.  For endomysium, you could probably use basement membrane collagen type IV just to see where it should be, but it will not define the extent of it.  Good luck!

Thank you, it's better to know this than to keep looking. :)