I have added 0.01 to 0.05 % glutaraldehyde (25% in water) in the milk, keeping 1hr and then heated 850C for 30 min. After separation of serum and casein parts, I have applied in the SDS-PAGE to observe the k-casein dissociation and micelle integrity. As I know, Glutaraldehyde has cross-linking power and maintain the casein micelle integrity. But I have found all micelle disrupted in case of 0.03 to 0.05% glutaraldehyde addition. How can I solve this or any idea to stop k-casein dissociation by the addition of glutaraldehyde application?