![]() ![]() Since these metabolites are present in blood, these antibodies may cross react with estradiol but will give test results that are too high because they recognize both authentic estradiol and its sulfate and glucuronide derivatives. Researchers have tried different immunogens with differing attachment chemistries, but the seemingly insurmountable problem is that mice appear to metabolize the estradiol immunogens to their sulfate and glucuronide derivatives and then they make antibodies to the derivatives. ![]() Attempts to make mouse monoclonals to estradiol have been uniformly unsuccessful. Pools of polyclonals eventually run out and there is no guarantee that immunizing other animals will yield a useable antibody.Įstradiol is a good case study to illustrate some of these issues. It is true that more antibody must be produced either in cell culture or in ascites, but the difficult and risky task of isolating the desired cell line never has to be repeated. Monoclonals have another important advantage over polyclonals in that once the monoclonal line is established, the supply of that particular antibody is essentially infinite. Ovulation and pregnancy are related but clearly different conditions. Early polyclonal pregnancy tests could show false positives because the assay detected an LH surge during ovulation due to cross reactions between an antibody raised to hCG with LH. hCG shares common subunit building blocks with TSH, LH and FSH. An example of this would be a test for hCG, the hormone that shows rapidly increasing levels in blood and urine during the early stages of pregnancy. Polyclonals contain hundreds or even thousands of specificities that can lead to cross reactions that can compromise an otherwise excellent test. They only react with one epitope on the target molecule. Their specificity is the most obvious one. Monoclonal antibodies have several advantages over polyclonals for routine production of diagnostic tests. Good manufacturing practices demand that cell banks be created and stored in different locations to ensure a continuing supply of a given monoclonal antibody.Ī central European company offers a monoclonal antibody project for under $6,000 and cites a time frame of about 3 months from immunization to initial samples of antibody. A single fusion can lead to several hundred individual cell lines, all of which must be screened and isolated so that a true monoclonal antibody with only one specificity can be assured. Once the mouse has shown an adequate polyclonal response, the animal is euthanized and the spleen cells are fused with a mouse myeloma line to yield immortal cell lines. Production of monoclonals is more technically complex. Additional booster injections and keeping the animals longer were offered at additional yet modest costs. With a coating titer of 1:10000 and a coating volume of 100 uLs, that size pool should be sufficient to produce 100,000 96-well microtiter plates or >1,000,000 lateral flow strips.Ī company in Massachusetts recently quoted a cost of $1,000 to develop a rabbit polyclonal antibody to a small molecule in about a month. A pool of 100 mL developed over a year is not unusual. ![]() These sera are accumulated and tested for titer and other relevant parameters before being pooled if the individual sera are similar enough. This blood yields about 20 mLs of useable serum after processing. It is possible to take about 40 mLs of blood from a healthy rabbit once a month for several years with no ill effects on the animal’s health. Once the desired response has been achieved, production bleeds can begin. Detectable antibodies can be seen in a few months of boosting, but a really good polyclonal response can take 6 to 9 months to fully mature. Repeated immunizations are key for making good antibodies in any species. Rabbits, goats and sheep are the most common subjects for making polyclonal antibodies and mice are the starting point for most monoclonals. This blog explores these advantages in the context of lateral flow assays.īoth monoclonal and polyclonal antibodies start out in much the same way: immunization of a live animal. However, the older models still have many advantages. Should you select polyclonal or monoclonal antibodies for your lateral flow rapid test? Some readers are probably wondering why polyclonal antibodies are not a thing of the past, like manual transmissions on cars and telephone landlines. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |