The HYDRAGEL CSF ISOFOCUSING test is based on the principle of isoelectric focusing on agarose gel, followed by immunofixation. The patient’s serum and CSF samples are analyzed in parallel to compare the distribution of IgG.

Before performing the test, it is essential to quantify IgG in both fluids in order to adjust the IgG concentration to the same level in CSF and serum.
After separation of proteins based on their isoelectric point, the gel is directly incubated with a peroxidase-labeled anti-IgG antiserum, without the need for membrane transfer.
The gel is then treated to remove unbound proteins before the enzymatic reaction.
Finally, the gel is visually evaluated.