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Thread: Info on IGF-1
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03-24-2004, 05:51 PM #1
Info on IGF-1
Long™R3IGF-I
Recombinant analog of human insulin growth factor-I
CATALOG NO. 85580
Description
Long™R3IGF-I is a recombinant analog of human insulin-like growth factor-I (IGF-I) that has been specifically engineered for the enhancement of cell culture performance. Long™R3IGF-I is more biologically potent in vitro than either insulin or native IGF-I and has been documented to
significantly increase recombinant protein production. It is ideal for both research and large-scale culture systems utilizing serum-free or low-level serum applications. Long™R3IGF-I is effective in any cell that contains type I IGF receptors, including most Chinese Hamster Ovary (CHO) lines, hybridomas and fibroblasts. Long™R3IGF-I is produced in a patented E. coli expression system without the use of animal-derived components.
Precautions
This product is for research/laboratory use. THIS PRODUCT
IS NOT INTENDED FOR HUMAN OR THERAPEUTIC USE.
Storage
Long™R3IGF-I in lyophilized form should be stored at 2 to 8 C and is stable for at least 3 years. Liquid solutions of Long™R3IGF-I (prepared as described below) can be stored
at 2 to 8 C and are stable for at least 2 years.
Preparation Instructions
1. Long™R3IGF-I is supplied lyophilized in an atmosphere of nitrogen at a slight vacuum (-25 kPa). Remove the metal cap from the glass vial and introduce an air filled syringe
through the septum to equalize the pressure.
2. Add sufficient 10 mM HCl or 100 mM acetic acid solution to the vial to achieve a peptide concentration of at least 0.1 mg/mL. Concentrations of 1 mg/mL or more are recommended.
3. Mix the solution thoroughly to insure the peptide is completely dissolved.
4. Filtration of a Long™R3IGF-I solution or a culture medium after the addition of Long™R3IGF-I should be performed using a low protein-binding membrane such as Polyvinyl Idene Flouride (PVDF), Poly Ethylene Sulfite (PES) or Cellulose Acetate (CA).
Methods for Use
Once Long™R3IGF-I has been reconstituted, it can then be added directly to cell culture medium. A titration of Long™R3IGF-I should be performed for each different application as the optimum concentration may vary depending upon the cell type used and other components present in the medium. The recommended final concentration range of Long™R3IGF-I is 10 to 50 µg/L (or ng/mL). Because Long™R3IGF-I and insulin may compete for the same cell receptors, the effectiveness of Long™R3IGF-I will be masked if it is added in conjunction with commonly employed concentrations of insulin (1 to 10 mg/L). However, inclusion of physiological levels of insulin (5 to 10 µg/L) in cell culture medium containing the recommended levels of
Long™R3IGF-I results in beneficial synergistic effects in certain applications.
Characteristics
Appearance
White powder
Molecular weight
9110 ± 2 daltons (Mass spectroscopy)
Endotoxin
< 0.1 EU/µg
Biological Activity
ED50 < 10 ng/mL (Bioassay assessing the stimulation of
protein synthesis in L6 myoblasts)
Identity/Consistency
Confirmed by N-terminal sequence analysis and HPLC
References
1. Francis, G., et al. J. Mol. Endocrinol. (1992) 8:213.
2. Thomas, J., Fung, V. Animal Cell Technology: Products of
Today, Prospects for Tomorrow (1993) 91.
3. Morris, A., Schmid, J. Biotechnol. Prog. (2000) 16:693.
JohnnyB
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03-24-2004, 05:54 PM #2
This ones on hIGF-1 thanks einstein1905
Pharmaceutical Research. Vol. 14, No.5. 1997
Solvent Effects on the Solubility and Physical Stability of Human Insulin- Like Growth Factor I
Purpose. The solubility and physical stability of human Insulin -like Growth Factor I (hIGF-l) were studied in aqueous solutions with differ- ent cxcipients.
Methods. The solubility of hlGP-r was determined by UV-absorption and quantification of light blocking particles. The physical stability of hlGF-r was studied with differential scanning caJorimetry (DSC) and circular dichroism (CD) spectroscopy.
Results. Human IGF-l precipitated at Jow temperature in the presence of J40 mM benzyl alcohol and 145 mM sodium chloride. CD data showed that the tertiary structure of hIGF-I during these condions was perturbed compared to that in 5 mM phosphate buffer. In the presence of benzyl alcohol 290 mM mannitol stabilized hIGF-I. Sodium chloride or mannitol by themselves had no effect on either the solubility or the tertiary structure. Benzyl alcohol was attracted to hIGF-l, whereas sodium chloride was preferentially excluded The attraction of benzyl alcohol WIlS reinforced by sodium chloride leading to salting-out of hlGF-l. The CD-data indicated interactions of benzyl alcohol with phenylalanine in hIGF-i. Thermal denaturation of hIGF-I occurred in all solutions with sodium chloride. whereas mannitol or benzyl alcohol had no effect on the thermal stability. The thermal stability of hIGF- I WIlS thus decreased in 145 mM sodium chloride although it WIlS excluded from hIGF-I.
Conclusions. The self-association and thermal aggregation of hIGF-I is driven by hydrophobic interactions. Benzyl alcohol is attracted to hIGF-I and induces changes in the tertiary structure causing hydropho- bic attraction of the protein at low temperatures.
Jonas Fransson,1,2,4 Dan Hallen,3 and Ebba Florin-Robertsson, 1
Received October 29, 1996; accepted February 19. 1997
1 Department of Pharmaceutical Technology, Pharmacia & upjohn, S-112 87 Stockholm, Sweden
2 Department of Pharmaceuticlas, Faculty of Pharmacy, Uppsala University, Box 570, S-751 23 Uppsala, Sweden
3 Department of Structural Chemistry, Parmacia & Upjohn, S-112 87 Stockholm, Sweden
4 To whom correspondence should be addressed. (e-mail: [email protected])
JohnnyB
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03-24-2004, 06:15 PM #3
That's a different view.The site from down under seems to lean towards HCL as the solution for stability.Quite a few conflicting studies done on this topic and IGF-1 in general.
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03-24-2004, 08:15 PM #4
I know it's can be hard to sort out, but I believe that BA is fine. Of course I get my view from these studies
JohnnyB
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03-24-2004, 09:33 PM #5Originally Posted by JohnnyB
I'd still love to see any study that compares activity in a few different solvent conditions or in any solvent conditions but over time.
It still is comforting to see GP's handling instructions saying that after reconstitution, it can be stored for up to 2 years. That should somewhat put to rest the myth of IGF-1 being so incredibly sensitive to degradation.
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03-25-2004, 09:07 AM #6
I've has mine for 4 months before suing and it's fine
JohnnyB
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03-25-2004, 11:27 AM #7
that impressive. i had mine for about 25 min before using it
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03-25-2004, 12:13 PM #8Originally Posted by SLUMPBUSTR
JohnnyB
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