IgG, CSF; Albumin, CSF; IgG Index; Serum IgG; Serum Albumin
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IgG Index, CSF + Serum
Test ID: IGI CS
Test
Method
Various
Method Description
IgG Index:(CSF IgG/Serum IgG) X (Serum albumin/CSF Albumin) X 100
Serum Albumin – Beckman Coulter AU680
PRINCIPLE: At pH 4.2, albumin from the sample combines with BCG reagent to form an intense green complex. The change in absorbance of the albumin-BCG complex is measured bichromatically (600/800 nm). This change in absorbance is directly proportional to the concentration of albumin in the sample.
Serum IgG – Beckman Coulter AU680
PRINCIPLE: Immune complexes formed in solution scatter light in proportion to their size, shape and concentration. Turbidimeters measure the reduction of incident light due to reflection, absorption or scatter.
In the procedure, the decreases in intensity of light transmitted (increase in absorbance) through particles suspended in solution is the result of complexes formed during the antigen-antibody reaction.
CSF Albumin – Cobas C6000
PRINCIPLE: The quantitative determination of Albumin in CSF is based on an immunoturbidimetric assay.
Anti-albumin antibodies react with the antigen in the sample to form antigen/antibody complexes which, following agglutination, are measured turbidimetrically.
CSF IgG – Cobas C6000
PRINCIPLE: The quantitative determination of IgG in CSF is based on an immunoturbidimetric assay.
Anti-IgG antibodies react with antigen in the sample to form an antigen-antibody complex. Following agglutination, this is measured turbidmetrically. Addition of polyethylene glycol allows the reaction to progress rapidly to the end point, increases sensitivity, and reduces the risk of samples containing excess antigen producing false negative results.
Platform
Serum: Beckman Coulter AU680; CSF: Cobas C6000
Report Includes
Specimens
CSF & Serum
Test Version
16-Jul-2025
Specimen
Specimens
CSF & Serum
Sample Volume
CSF: 0.5mL; Serum: 0.5 mL
Collection & Handling
Handling Information
Store and send frozen – specimen must be received at ICL within 5 days of collection.
Rejection Criteria
| Specimen | Plasma |
|---|
Test Version
16-Jul-2025
Performance / Interpretation
Method
Various
Method Description
IgG Index:(CSF IgG/Serum IgG) X (Serum albumin/CSF Albumin) X 100
Serum Albumin – Beckman Coulter AU680
PRINCIPLE: At pH 4.2, albumin from the sample combines with BCG reagent to form an intense green complex. The change in absorbance of the albumin-BCG complex is measured bichromatically (600/800 nm). This change in absorbance is directly proportional to the concentration of albumin in the sample.
Serum IgG – Beckman Coulter AU680
PRINCIPLE: Immune complexes formed in solution scatter light in proportion to their size, shape and concentration. Turbidimeters measure the reduction of incident light due to reflection, absorption or scatter.
In the procedure, the decreases in intensity of light transmitted (increase in absorbance) through particles suspended in solution is the result of complexes formed during the antigen-antibody reaction.
CSF Albumin – Cobas C6000
PRINCIPLE: The quantitative determination of Albumin in CSF is based on an immunoturbidimetric assay.
Anti-albumin antibodies react with the antigen in the sample to form antigen/antibody complexes which, following agglutination, are measured turbidimetrically.
CSF IgG – Cobas C6000
PRINCIPLE: The quantitative determination of IgG in CSF is based on an immunoturbidimetric assay.
Anti-IgG antibodies react with antigen in the sample to form an antigen-antibody complex. Following agglutination, this is measured turbidmetrically. Addition of polyethylene glycol allows the reaction to progress rapidly to the end point, increases sensitivity, and reduces the risk of samples containing excess antigen producing false negative results.
Platform
Serum: Beckman Coulter AU680; CSF: Cobas C6000
Turnaround Time
10 days
Results
| Name | Units | Reference Range | Conversion Factor | |
|---|---|---|---|---|
| IgG, CSF | g/L |
|
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| Albumin, CSF | g/L |
|
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| IgG Index |
|
|||
|
IgG Index = (CSF IgG/Serum IgG) X (Serum albumin/CSF Albumin) X 100
|
||||
| Serum IgG | g/L |
|
||
| Serum Albumin | g/L |
|
||
Test Version
16-Jul-2025
Interface / Setup
HL7 Interface Codes
| Order Code | Result Codes | Units |
|---|---|---|
| IGI CS | 3060IgG, CSF | g/L |
| 3061Albumin, CSF | ||
| 36612IgG Index | ||
| 63563Serum IgG | g/L | |
| 63564Serum Albumin | g/L |
Test Version
16-Jul-2025