Bovine Serum Albumin reagent adjust the zeta potential between the red cells , so the addition of BSA enhances such immunological reactions and increases test sensitivity
Centrifugation of the cells attempts to bring the red blood cells closer together, but even then the smaller IgG antibodies usually can not reach between two cells. The larger antibodies, IgM, can reach between cells that are further apart and cause agglutination.
* The concept Zeta potential is important to understand why the cells will maintain a certain distance from each other. Zeta potential refers to the repulsion between the red blood cells.It is due to an electric charge surrounding cells suspended in saline.
* It is cause by sialic acid groups on the red blood cell membrane which gives the cells a negative charge.
* The positive ions in saline attracted to the negatively charged red blood cells.
* The net positive charge surrounding cells in saline keeps them far apart due to repulsion from electric charges
* Smaller antibodies (IgG) cannot cause agglutination when zeta potential exists
* To overcome zeta potential techniques need to neutralize these charges One of the common techniques is:
1) Add albumin to test mixture
2) OH- groups of albumin neutralize positive charge
تعليق