Delipidation of egg yolk

• Dilute the egg yolk 1:10 with destiled water.
• Adjust the pH to 5.0 with 0.1 N HCl.
• Mix together and let it stand for at least 2 hours at 4°C.
• Freeze at -20°C for 24 hours. (Good way to store egg yolk for future processing)
• Thaw slowly at 4-6°C overnight.
• Filtrate on Whatman No. 52 filter paper at 4°C or centrifuge at 16 000 xg for 25 minutes at 4°C.
• Collect the supernatant (WSF - water soluble fraction) which contains IgY.

Practical notes:
This method is suitable for "rough" total IgY purification for testing as well as for applying on affinity column.
If the supernatant contains particles, it should be filtrated before loading on the column.
Method involves handling larger volumes compare to for example precipitation methods.

References Kim H. Abd Nakai S. (1996) Immunoglobulin separation from egg yolk: a serial filtration system. J.Food Sci. 61(3):510-512.
Kim H. And Nakai S. (1998) Simple separation of immunoglobulin from egg yolk by ultrafiltration. J.Food Sci. 63(3):485-490.