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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

IgG, CSF; Albumin, CSF; IgG Index

Specimens

CSF & Serum

Test Location

St. Michael's Hospital, 30 Bond Street, Toronto ON M5B 1W8

Test Version

12-Apr-2023

Specimen

Specimens

CSF & Serum

Sample Volume

2 mL

Specimen Comment

Plasma is not suitable.

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

12-Apr-2023

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
  • <0.060
Albumin, CSF g/L
  • 0.100 - 0.250
IgG Index
  • <70
IgG Index = (CSF IgG/Serum IgG) X (Serum albumin/CSF Albumin) X 100

Test Location

St. Michael's Hospital, 30 Bond Street, Toronto ON M5B 1W8

Test Version

12-Apr-2023

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

12-Apr-2023