There are probably many sources for anti mouse C-peptide (unconjugated), for example the following: 

Novus:

http://www.novusbio.com/primary-antibodies/c-peptide

Abcam:

http://www.abcam.com/c-peptide-antibody-ab14181.html

You may be able to find something suitable for your work in your location. If you cannot find biotin conjugated product, it is not very difficult to do it yourself these days. Pierce and several companies sell reliable reagents to perform conjugation. Post conjugation cleanup to remove excess reagents (biotin) is one step process.

You will need to optimize the ELISA to ensure that everything works reliably and repeatedly. In our lab we use in-house insulin ELISA. Before ELISA, we used an in-house radioimmunoassay. For C-peptide, we buy kits, partly because we require these measurements less frequently.

Unless you are planning to do C-peptide assays frequently on many samples, kits do have the advantage of fully optimized reagents/protocols and working reliably.

Best,

There are probably many sources for anti mouse C-peptide (unconjugated), for example the following: 

Novus:

http://www.novusbio.com/primary-antibodies/c-peptide

Abcam:

http://www.abcam.com/c-peptide-antibody-ab14181.html

You may be able to find something suitable for your work in your location. If you cannot find biotin conjugated product, it is not very difficult to do it yourself these days. Pierce and several companies sell reliable reagents to perform conjugation. Post conjugation cleanup to remove excess reagents (biotin) is one step process.

You will need to optimize the ELISA to ensure that everything works reliably and repeatedly. In our lab we use in-house insulin ELISA. Before ELISA, we used an in-house radioimmunoassay. For C-peptide, we buy kits, partly because we require these measurements less frequently.

Unless you are planning to do C-peptide assays frequently on many samples, kits do have the advantage of fully optimized reagents/protocols and working reliably.

Best,

You can follow the link below to secure certain crucial informations:-

http://www.pierce-antibodies.com/1/3/anti-mouse-c-peptide-antibody

Thank you very much for answers!

Try searching in:

http://www.linscottsdirectory.com/

http://www.linscottsdirectory.com/

If you need large amounts of antibody for large scale work, you may want to avoid throwing lots of money to Abcam or Novus or to ready-kits and go for a customized antibody (biotinylated and all). Obviously you will have to validate and optimize yourself in such case. A cost-effective approach comes from Everest Biotech who will make you goat antibodies affinity purified using the immunizing peptide (high yield).

Thank you all for replies. As a result I decided first try to use ELISA-kit from Japanese supplier (just because I need some preliminary results in nearest future).

As for further experiments, if the results will be as I expect, I will make in house ELISA using some antibodies that I can buy here in Japan and some customized antibodies.

By the way, thank you for the link to Linscott's Directory, it's a great thing.