[Histonet] shark egg carbohydrate jelly staining

[John Kiernan]

If the biochemistry of shark egg jelly is known
(as you indicate), it will probably be possible to
localize different carbohydrate components in
different colours. Are the carbohydrates bound to
protein, as glycoproteins or proteoglycans? If so,
they will be fixable with formaldehyde and you will
be able to do the staining the usual way - on sections 
rather than whole specimens. Even if the jelly is
protein-free it must consist of very large polysacharide
molecules at least in the mucous and solid layers, and
can probably insolubilized by a suitable fixative.

The choice of staining methods for carbohydrates is
quite large, and it's possible to collect significant
chemical information. These techniques have all 
been developed for sections (usually paraffin). Some
of the simpler techniques can be applied to very small 
(0.5 mm) whole objects that are later embedded and
sectioned for electron microscopy.

How big is a shark's egg? That affects the technology!
If you can provide more biochemical information about
shark egg jelly, I (and others reading Histonet
messages) will be able to advise you about preparative
techniques and staining methods.

John A. Kiernan
Dept of Anatomy & Cell Biology
University of Western Ontario
London,  Canada  N6A 5C1
_____________________________________________
Jen Wyffels & Greg Shafer wrote:
> 
> I would like to stain the carbohydrate jelly in a shark egg.  The egg is
> similar to a chicken egg, the yolk is surrounded by a protective matrix but
> in sharks it is carbohydrate rather than albumen.  I will remove the yolk
> leaving the egg jelly within the egg shell.  This jelly has 3 distinct and
> separate compositions, a water like layer (1), a 'snot' like layer (2) and
> finally a very dense solid (3).  I would like to immerse this egg in a
> carbohydrate stain that would show the layers and their distribution withing
> the egg case.  These layers have been shown (after complete hydrolysis) to
> differ in the concentration of sugar moeties present with the dense layer
> containg the highest concentrations.  Has anyone tried something similar and
> willing to share their results?  I can experiment a little but egg
> availability is limited so any advice is welcome.  Thanks,  Jen
> 
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