CNS Local IgG synthesis detection by isoelectrofocusing

The gold standard assay to objectively detect CNS local IgG synthesis in multiple sclerosis.

About CNS Local IgG synthesis detection by IEF

Presence of intrathecal IgG suggests inflammatory disease of the Central Nervous System, such as caused by multiple sclerosis (MS).

The HYDRAGEL CSF ISOFOCUSING kit used on the HYDRASYS 2 SCAN FOCUSING instrument provides qualitative detection and immunological characterization of IgG oligoclonal banding in human CSF (Cerebro Spinal Fluid) and serum. The semi-automated HYDRASYS instrument enables migration, immunofixation and direct detection on agarose gels, in order to obtain IgG profiles for qualitative analysis.

The main recommendations of European Consensus Report for Multiple Sclerosis diagnosis are:

  • Isoelectrofocusing (IEF) on Agarose gel for immunoglobulins separation
  • Use of non-concentrated CSF material
  • Simultaneous analysis of the patient’s serum and CSF
  • Identical IgG concentration in paired CSF-serum samples


The presence of CSF oligoclonal bands only, characterizing local IgG synthesis, tightly correlates with the diagnosis of Multiple Sclerosis. Their presence provides useful information when in agreement with the other clinical investigations.

Key benefits

Accurate Diagnosis of inflammatory disease of the CNS

Sensitivity increased about a 100-fold compared to standard immunofixation thanks to the detection with enzyme labelled antibodies.

Efficient Method

Clear oligoclonal band visualization for a reliable interpretation.

Faster result

Simple step-by-step procedure without membrane transfer for 3 hours of turnaround time.

Compliance with international consensus

HYDRAGEL CSF ISOFOCUSING meets all requirements needed to objectively detect CNS local IgG synthesis in multiple sclerosis.

Detection limit of an IgG band:
0.31 mg/L
Detection limit of an IgG band:
0.31 mg/L

Main characteristics

Test Principle

The HYDRAGEL CSF ISOFOCUSING assay is based on the principle of agarose gel isoelectrofocusing followed by immunofixation. The patient’s serum and CSF samples are analysed in parallel to compare the IgG distribution.


  • Prior to performing the test, it is mandatory to quantify the IgG’s in both liquids, in order to adjust the IgG concentration at the same level in CSF and serum.
  • After the protein separation according to their isoelectric point, the gel is directly incubated with a peroxidase labelled anti-IgG antiserum, with no need for a membrane blotting step.
  • Then, the gel is processed to remove unbound proteins before the enzymatic reaction.
  • Finally, the gel is visually evaluated.
Sample Type

Serum and CSF samples are performed in parallel for each patient to compare IgG distribution as recommended by the European consensus.

  • 2 stages-protocol: Isoelectrofocalisation and Immunofixation for an optimized result
  • Enhanced software with high voltage monitoring
  • Full traceability and positive ID obtained by connecting the HYDRASYS instrument to the ASSIST pipetting station
Product details

Flexible Format of HYDRAGEL CSF ISOFOCUSING kit: 10 gels of 3 or 9 tests.