Abstract |
A method for the determination of human granulocyte colony-stimulating factor (hG-CSF) activity, based on stimulation of cellular proliferation, was developed using a subclone of the murine myeloid leukemia cell line NFS-60, with an improved sensitivity for hG-CSF, as indicator. The optimal range for quantitative analysis of hG-CSF was about 4-60 pg ml-1. The stimulatory effect was measured by a colorimetric microassay: the optical density of formazan, which is produced by viable cells from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), was obtained by reading plates in a multi-channel photometer. The assay was designed as a five-dose parallel line test, employing three or four doses for potency determinations, which fulfil pharmacopoeial requirements for assay validity. Inter-assay relative standard deviation (RSD) varied between 5.2 and 12.0%. Most assay experiments revealed potencies within limits of error of 90-110% and the mean index of precision value was 0.057. The recently developed yeast cell-derived International Standard (88/502) served as a reference for activity of rhG-CSF. Specificity of the assay was demonstrated by absence of response upon exposure to a panel of biomolecules, including recombinant human interleukin-3, and by the suppression of growth stimulation in the presence of neutralizing anti hG-CSF antibodies. Potency readings of unglycosylated rhG-CSF were dependent on pH of assay medium with higher relative activities observed at pH 6.6 than at 7.4. Moreover, SDS-PAGE analysis of the carbohydrate-deficient preparation, following incubation at physiological pH, revealed several high molecular weight rhG-CSF bands and decreased monomeric form. The method described was found suitable for potency assessments of pharmaceutical formulations of hG-CSF.
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Authors | U Hammerling, R Kroon, L Sjödin |
Journal | Journal of pharmaceutical and biomedical analysis
(J Pharm Biomed Anal)
Vol. 13
Issue 1
Pg. 9-20
(Jan 1995)
ISSN: 0731-7085 [Print] England |
PMID | 7536474
(Publication Type: Journal Article)
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Chemical References |
- Formazans
- Recombinant Proteins
- Tetrazolium Salts
- Granulocyte Colony-Stimulating Factor
- MTT formazan
- Sodium Dodecyl Sulfate
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Topics |
- Animals
- Cell Division
(drug effects)
- Electrophoresis, Polyacrylamide Gel
- Evaluation Studies as Topic
- Formazans
- Granulocyte Colony-Stimulating Factor
(metabolism, pharmacology)
- Heating
- Humans
- Leukemia, Myelomonocytic, Acute
(pathology)
- Mice
- Photometry
- Recombinant Proteins
(analysis, pharmacology)
- Sensitivity and Specificity
- Sodium Dodecyl Sulfate
- Tetrazolium Salts
- Tumor Cells, Cultured
(drug effects)
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