Immuno Assays

This procedure is best described in Thein and Landry s word s  

---

An immuno assay for a-1-fetoprotein has been developed with microgels by binding antibodies to their surface [291,375]. With corresponding antigenes in solution these microgels aggregate to form much larger particles which can be detected by photon correlation spectroscopy. 

Funke, C. et al., Harbor seal (Phoca vitulina) C-reactive protein (C-RP) purification, characterization of specific monoclonal antibodies and development of an immuno-assay to measure serum C-RP concentrations, Vet. Immunol. Immunopathol., 59, 151, 1997. 

Viral structural proteins expressed by baculovirus infected insect cells assemble into multimeric structures that resemble viral core-like particles and virus-like particles (CLPs and VLPs, respectively). This presentation has brought the attention of researchers for the potential use of these structures as safe immunological reagents for virus or antibody detection in enzyme immuno assays, as vaccines, and more recently, as gene delivering systems for gene therapy [9]. 

Use of a surrogate end point that is quick and easy to obtain Permeation experiments using a radiolabeled, fluorescent, HPLC-detectable, or radio immuno assay/enzyme linked immuno sorbent assay-detectable marker necessitate the need of extensive sample handling and sample analysis. This accentuates the cost of sample analysis and overall time spent in characterizing the efficacy of formulations. Furthermore, current state of the art fluidics systems put a fundamental limit on the number of samples handled in a given time. 

Fig. 18.6. Calibration curve obtained by the immuno-assay procedure in the detection of anti-E2 using the ITO-Poly (pyrrole-benzophenone) coated optical fibers. The linear range of the calibration curve was obtained for titer 1 64,000 and lower. The curve was fitted according to the equation y = A+B(x), where x is the human sera (anti-E2 antibodies) dilution value and y is the chemiluminescence response. The obtained correlation coefficient was R2 = 0.988.

Gaines-Das RE, Meager A (1995), Evaluation of assay designs for assays using microtitre plates results of a study of in vitro bioassays and immuno-assays for tumor necrosis factor, Biologicals 23 285-297. 

Of the other established methods one can be less certain. Electrochemical methods, other than ion selective electrodes, seem to be practised more in academic laboratories than industrial, and are prone to fundamental problems relating to electrode contamination and chemical interferences. Nuclear methods would seem to have reached their apogee (if one classifies radio immuno assay as biological rather than nuclear) and the same seems to be true of thermal methods. This is not to say that these methods will not continue to be used and to be important. It is a comment that despite the missionary work of numerous adherents of these methods, one notes in the large industrial laboratories much more application of and enthusiasm for spectroscopy, chromatography and biological methods. 

We have measured FSH in unextracted urine on an AxSYM random-access immunoassay analyzer (Abbott laboratories, Abbott Park, IL) with a MEIA (microparticle enzyme immuno assay) reagent kit. In order to correct for dilution, creatinine was measured, and the urinary FSH was normalized for creatinine concentration. Urine and serum samples were obtained from 40 women between 32 and 55 years of age. All women were healthy, except for a benign gynecological illness for which they were admitted to our hospital. All women had normal renal function. On the day of operation, we took six serum samples from each patient, each at least an hour apart, in order to calculate the mean serum FSH concentration. During the same day, we collected an early-morning urine sample, 24-h urine sample, and a random void urine sample. 

Luminescence immuno assays have been discussed in detail in Chapter 12. Some other techniques are listed below with pertinent references ... 

Figure 3 Adsorption IgG to a series of poly(lauryl methacrylate-co-glycerol methacylate-co-ethylene glycol dimethacrylate)s Results from immuno assay, optical density is directly proportional to amount of adsorbed protein...

High Performance Liquid Chromatography 7.10. Enzyme Immuno Assay... 

Maertlbauer et al. [34] developed a highly specific and sensitive enzyme immuno assay for the quantitative determination of natamycin in cheese rind. Rabbits were immunized with a natamycin-HSA conjugate to produce a specific antiserum. A labelled ligand was produced by coupling natamycin to horseradish peroxidase. The range of this ELISA test was between 0.2 and 2 ng per ml of sample solution. This allowed the determination of natamycin in cheese rind down to concentrations of 5 ng/dm2 or 0.1 mg/kg. The recovery in a range of 1 to 80 mg/kg was 76 to 84%. The cross-reactivity with amphotericin B and nystatin was <0.001%. 

Tanaka T, R. Sato R, Kamiya S, Obata K, Tamiya S, Matsunaga T. (2000). Fully-automated heterogeneous immuno assay of human insulin using protein A-bacterial magnetic particle complexes. Anal. Chem. 72,3518- 3522... 

PARAMETER MALS (BioSentry Chemical Physical Monitors Rapid PCR ATP Lumincs ccncc Immuno- assays... 

Tjjssen, P. (1985). Practice and Theory of Enzyme Immuno assay, Elsevier, Amsterdam... 

---