Patience is the key.  It is slow to wet.  Do not vortex or  ticturate it.  Just float it on top of warm saline and stir it gently.  I routinely make 75 mg/ml solutions of EMD Millipore 3#415731GM. 

sir,

i have attached a paper.

sir,

i have attached a paper.

you can dissolve it in Tris-HCl buffer.

thanks packia lincy for the suggestion. i had tried it with 0.9 % saline ... and tried to make 5mg/ml solution. but i could see some clumps .. i will try reducing fibrinogen concentration . 

Thanks willo Hessen for the suggestion ... At what concentration and pH should use tris hcl buffer.?

you could try sonicating it

Sonicating even for 30mins will not give a positive result in dissolving fibrinogen. I have tried at temp. around 40C, the fibrinogen dissolves very slowly at 1% saline giving a slight haziness to liquid but their will be some undissolved parts left behind. Changing the pH also is in effective.

can one use PBS ?

Patience is the key.  It is slow to wet.  Do not vortex or  ticturate it.  Just float it on top of warm saline and stir it gently.  I routinely make 75 mg/ml solutions of EMD Millipore 3#415731GM. 

Tris H Cl pH 8 ,0.2 M 

Tris is toxic to cells.  this does not work if you are embedding cells in the gel.

You can dissolve in 25mM MES/150mM Nacl buffer, dissolve at 37 ℃. It takes long time,normally I left them overnight at 37 ℃. But do not vortex because it might cause denature of the fibrinogen.

How do you filter sterilize it when it's so viscous? I'm trying to filter sterilize 50 mg/ml fibrinogen.

Alexandra Quezada Maybe consider lowering the concentration slightly? I 0.22 um filter sterilize 20 mg/ml solutions with a syringe + button filter (as suggested here https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/f8630pis.pdf) and it seems to go through fine!

James Funderburgh is accurate. I've made 125mg/mL solutions (12.5%) in the same manner. It helps if you add the Fbgn in small amounts over time