Theoretical and experimental investigation of immunoprecipitation pattern formation in gel medium

Morphology and Composition of Immunodiffusion Precipitin Complexes Evaluated via Microscopy and Proteomics

“…Our results in this study broadly support the findings and hypotheses of Fedorov et al, pertaining to the expected microstructure of the precipitin rings. − Upon inspection with CLSM and SEM of the immunodiffusion gels as a function of time, we clearly observed individual microparticles within the expected size range of 10 2 to 10 3 nm. We also observed an increase in the size of these particles via CLSM, especially in the 10–20 h mark; however, it is unclear whether or not the growth of initial clusters is favored over the formation of new clusters.…”

“…We also observed an increase in the size of these particles via CLSM, especially in the 10–20 h mark; however, it is unclear whether or not the growth of initial clusters is favored over the formation of new clusters. In our study, the particles formed are larger than those predicted by Fedorov et al; however, this is likely due to systematic differences in the hydrogel properties, different antigen/antibody species, etc. In future studies, it would be intriguing to separate and characterize these nano/microparticles via conventional methods ( e.g.…”

“…Fedorov and colleagues recently performed studies to shed some light on the broad morphology of ID assays with the use of mathematical models and light microscopy. − After validating their reaction/diffusion model with experimental data, they suggested that the precipitin ring structure is actually a network of antigen/antibody complexes, which become large enough to block pores and scatter light, hence forming a visible set of clusters that together form the characteristic precipitin ring . They propose that these precipitin complexes could be several hundreds of nanometers in size and that the growth of initial complexes would be favored over the initiation of new species.…”

“…Fedorov et al also demonstrated that the precipitin ring structure is reflective of the nature of the antibody used in the assay. Monoclonal antibodies yielded single precipitin rings in the gels, whereas polyclonal antibodies produced a number of rings, while mixtures of individual monoclonal antibodies produced a unique ring for each antibody employed. , While these studies have helped link ID phenomena to analytical diffusion/reaction models, the detailed structure and proteomic composition of the precipitin rings remain unknown. A thorough understanding of the proteins involved in precipitin ring formation could open up avenues for designing novel tests with enhanced sensitivity and faster turnaround times.…”

“…23−25 After validating their reaction/diffusion model with experimental data, they suggested that the precipitin ring structure is actually a network of antigen/antibody complexes, which become large enough to block pores and scatter light, hence forming a visible set of clusters that together form the characteristic precipitin ring. 25 They propose that these precipitin complexes could be several hundreds of nanometers in size and that the growth of initial complexes would be favored over the initiation of new species. Complex diffusion is driven by the concentration gradient between the central well saturated with the antigen and the hydrogel substrate that is homogeneously saturated with the antiserum.…”