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Can you provide MSDS or Certificates of Analysis?
For MSDS or Certificates of Analysis please send requests via Tech Support.
Why don't your products have expiration dates?
Our products are used for a wide variety of applications, and it is possible that the ideal expiration date for each of these applications may be different. Factors such as storage conditions, number of times a product is frozen and thawed, number of steps in a manufacturing processes or if preservatives are added can also affect the quality of the product. It is in the best economical interest of the customer to determine the expiration date empirically.
What is the difference between gamma globulin and IgG?
In the past the terms were used interchangeably, but there is a difference. There are IgGs in the gamma globulin fraction along with the other gamma globulin proteins but only gamma globulin G is in the IgG fraction.
When blood serum is placed on a specific medium and exposed to an electric current, the various proteins migrate to form bands according to their electrophoretic mobility and indicate the relative proportion of each protein fraction. The gamma globulin fraction band of serum usually contains at least 3 of the 5 Immunoglobulin proteins which migrate together. The highest percentage are Immunoglobulin G (IgG), followed by Immunoglobulin M (IgM) , and then an even smaller percentage of Immunoglobulin A (IgA). The gamma fraction may also contain traces of Immunoglobulin D & E. The gamma globulin fraction can then be further fractionated into its separate components. The IgG fraction makes up the majority of the gamma globulin fraction.
When the Immunoglobulin G fraction is removed from the other gamma globulins, it is called IgG. The purity of the IgG can be measured and given as a % of the total solution, number of mgs in solution and the relative concentration of that solution. The more 'pure' a solution is, the more difficult it is to manufacture, thereby raising the cost of the product.
Can your rabbit complement be used for cytotoxicity assays?
Yes! Evidence suggests that the proteins participating in the transmembrane channel formation are structurally interrelated. After further explorations of these relationships between the terminal components of the complement system, it has become clear that all five proteins, C6, C7, C8, C9, and C9RP (also called "cytolysin", "perforin", or "pore-forming protein"), share certain antigenic properties. C9-related protein (C9RP) is the protein responsible for pore-forming activity. Because the protein interacts with C9, it has been called C9-related protein, a term synonymous with cytolysin , perforin (an effector molecule of killer T-cells and NK cells), and pore forming protein. Although C9 and C9RP are similar, probably homologous proteins, and may be analogous in their function, they differ in that isolated C9RP is cytotoxic by itself, whereas isolated C9 is not. Under certain conditions, C9RP kills cells without the participation of other proteins. For C9 to exert its cytotoxic effect it requires cell-bound C5b-8. Rabbit complement seems to have fewer proteins that kill cells independently and so it is often a good choice for specific antigen/antibody reactions.
What is the functional difference between young rabbit complement and 3-4 week rabbit complement ?
Young rabbit complement comes from rabbits that are from 8-10 weeks of age as opposed to the 3-4 week old rabbits. Newborn rabbits have almost no immunity when they are born but upon exposure to foreign antigens they begin to produce complement as a first line of defense. Sometime during the 5-6 week of life they begin to produce antibodies to their environment. Among those antibodies there are what is referred to as 'heterophile' antibody. In some sensitive assays the heterophile antibody reacts nonspecifically and will mask the specific reaction and cause false results.
You may hear some technicians describe this phenomenon as the complement's being 'toxic' to the cells. The 3-4 week old complement avoids this situation and is used in specific research projects. However, the 3-4 week old complement may not be 'strong' enough to bind weak antigens. This is why complement from 8-10 week old rabbits is used in tissue typing.
For best results, it is wise to thaw in cool water, swirl to expedite thawing and use immediately. To keep the complement active do not thaw and refreeze for usage at another time.
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