id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-022200-hqc8r31t	HYATT, ALEX D.	Protein A–Gold: Nonspecific Binding and Cross-Contamination	2012-12-02		.txt	text/plain	3586	225	56	Some potential problems associated with protein Α -g o l d labeling are also associated with other immunocytochemical techniques, namely nonspecific staining (for example, nonspecific antibodies and electrostatic at tachment; Taylor, 1978; Behnke et al., 1986; Gosselin et al., 1986; Birrell et al., 1987) . In double-labeling experiments cross-contamination is now recognized as a problem which arises from the affinity which protein A possesses for different regions of IgG antibodies, namely the Fc and Fab regions (Roth, 1982; Endresen, 1979; Zikan, 1980) . If the larger of the gold probes is used for the visualization of the first antigen, many potential Fc binding sites (unoccupied protein A) are available for the second immunoglobulin and significant cross-contamination may therefore result. If protein Α-gold is the label, and nonspecific binding and cross-contamination are persistent problems in spite of the addition of excess free protein A, high-affinity stabilizers, adsorption of contaminat ing antibodies, and colloidal gold, then alternative labeling techniques should be pursued and evaluated.	./cache/cord-022200-hqc8r31t.txt	./txt/cord-022200-hqc8r31t.txt