CNS Local IgG synthesis detection by isoelectrofocusing

The gold standard assay to 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 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 from the European Consensus Report for Multiple Sclerosis diagnosis (detailed in “Recommended Standard of Cerebrospinal Fluid Analysis in the Diagnosis of Multiple Sclerosis .A Consensus Statement.” Arch. Neurol.62,863-870,2005) 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 serum and CSF samples in order to adjust the IgG concentration to the same level.
  • The proteins are first separated according to their isoelectric point, the gel is then incubated with a peroxidase labelled anti-IgG antiserum.
  • The gel is then processed to remove unbound proteins prior to the enzymatic reaction.
  • The gel is visually evaluated for the presence of CSF oligoclonal bands.
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
  • 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.