Immunolabeling efficiency of protein A-gold complexesL Ghitescu and M Bendayan Departement d'Anatomie, Universite de Montreal, Quebec, Canada. A systematic study of the adsorption of protein A on colloidal gold particles varying in size from 5-16 nm was performed at different protein concentrations. The number of protein A molecules bound per colloidal particle was evaluated and the Scatchard analysis of the adsorption parameters was applied for each size of the colloid. The binding of protein A to the colloidal gold surface exhibited the same affinity pattern for all of the particle sizes. At low concentrations of stabilizing protein, adsorption took place with high affinity (Kd 1.96-3.3 nM) and the maximum number of protein A molecules attached with this affinity correlated well with the surface of the particle. At higher concentrations of protein A, adsorption exhibited a significantly lower affinity (Kd 530-800 nM), and no saturation was recorded. Competition by albumin did not reveal a preferential removal of the "low-affinity" bound protein A molecules, contradicting the model of successive shells of stabilizing protein around the colloidal particle. The immunolabeling efficiency of conjugates having the same size of gold nucleus but carrying different numbers of protein A molecules was comparatively investigated by quantitative post-embedding immunocytochemistry. Protein A-gold formed with 5-10-nm colloids gave the highest intensity of labeling when carrying the maximum number of protein A molecules that could be adsorbed with high affinity. Overloading as well as underloading these complexes resulted in a significant decrease of their immunoreactivity. The most efficient conjugates were obtained when stabilization was performed with 6 micrograms protein A/ml gold sol of 5 and 10 nm particle diameter, and 15 micrograms protein/ml of 15-nm colloid.
Volume 38,
Issue 11,
pp. 1523-1530,
11/01/1990
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
M. Cloutier, D. Gingras, and M. Bendayan Internalization and Transcytosis of Pancreatic Enzymes by the Intestinal Mucosa J. Histochem. Cytochem., July 1, 2006; 54(7): 781 - 794. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Mayer, R. D. Leone, J. F. Hainfeld, and M. Bendayan Introduction of a Novel HRP Substrate-Nanogold Probe for Signal Amplification in Immunocytochemistry J. Histochem. Cytochem., April 1, 2000; 48(4): 461 - 470. [Abstract] [Full Text] |
||||
![]() |
J. M. Robinson, T. Takizawa, and D. D. Vandré Enhanced Labeling Efficiency Using Ultrasmall Immunogold Probes: Immunocytochemistry J. Histochem. Cytochem., April 1, 2000; 48(4): 487 - 492. [Abstract] [Full Text] |
||||
![]() |
J. G. White, M. D. Krumwiede, and G. Escolar Glycoprotein Ib Is Homogeneously Distributed on External and Internal Membranes of Resting Platelets Am. J. Pathol., December 1, 1999; 155(6): 2127 - 2134. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Lavoie, J. Paiement, M. Dominguez, L. Roy, S. Dahan, J.N. Gushue, and J.J.M. Bergeron Roles for {alpha}2p24 and COPI in Endoplasmic Reticulum Cargo Exit Site Formation J. Cell Biol., July 26, 1999; 146(2): 285 - 300. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Iborra and P. R. Cook The Size of Sites Containing SR Proteins in Human Nuclei: Problems Associated with Characterizing Small Structures by Immunogold Labeling J. Histochem. Cytochem., September 1, 1998; 46(9): 985 - 992. [Abstract] [Full Text] |
||||
![]() |
J. M. Robinson and D. D. Vandre Efficient Immunocytochemical Labeling of Leukocyte Microtubules with FluoroNanogold: An Important Tool for Correlative Microscopy J. Histochem. Cytochem., January 1, 1997; 45(5): 631 - 642. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Mercure, I. Jutras, R. Day, N. G. Seidah, and T. L. Reudelhuber Prohormone Convertase PC5 Is a Candidate Processing Enzyme for Prorenin in the Human Adrenal Cortex Hypertension, November 1, 1996; 28(5): 840 - 846. [Abstract] [Full Text] |
||||
![]() |
M Bendayan and E. Rasio Transport of insulin and albumin by the microvascular endothelium of the rete mirabile J. Cell Sci., January 7, 1996; 109(7): 1857 - 1864. [Abstract] [PDF] |
||||
![]() |
C. Velez-Granell, A. Arias, J. Torres-Ruiz, and M Bendayan Molecular chaperones in pancreatic tissue: the presence of cpn10, cpn60 and hsp70 in distinct compartments along the secretory pathway of the acinar cells J. Cell Sci., January 3, 1994; 107(3): 539 - 549. [Abstract] [PDF] |
||||
| Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact |