(N20345) permits attachment of these very small (1.4 nm) yet uniformly sized gold particles to

accessible thiol groups in biomolecules (Figure 2.2.38, Figure 2.2.39). NANOGOLD® monomaleimide,

which is supplied as a set of five vials of a powder lyophilized from pH 7.5 HEPES buffer,

is simply resuspended with the thiol-containing protein in deionized water at room temperature

or below to form the conjugate, after which any excess NANOGOLD® monomaleimide is

removed by gel filtration.102,103

In addition to its many uses for light and electron microscopy, NANOGOLD® monomaleimide

has been shown to be an extremely efficient quencher for dyes in molecular beacons—probes that

can be used for homogeneous fluorescence in situ hybridization assays.104 NANOGOLD® conjugates

of antibodies and streptavidin are described in Section 7.2 and Section 7.6, respectively, along

with reagents and methods for silver enhancement to amplify electron microscopy detection.104

Figure 2.2.38 Reaction of NANOGOLD® monomaleimide

(N20345) with a thiol. Image courtesy of Nanoprobes, Inc.

Figure 2.2.39 Scanning transmission electron microscope

(STEM) image indicating that labeling with NANOGOLD®

monomaleimide (N20345) occurs specifically at a hinge-thiol

site on the IgG molecule. Image courtesy of Nanoprobes, Inc.

REFERENCES

1. J Histochem Cytochem (2003) 51:1699; 2. PLoS One (2009) 4:e8115; 3. Proc Natl Acad Sci U S A (2006) 103:12831;

4. Proc Natl Acad Sci U S A (2003) 100:4001; 5. Proteomics (2006) 6:1385; 6. Lab Chip (2005) 5:1271; 7. Electrophoresis

(2005) 26:571; 8. Bioconjug Chem (2009) 20:702; 9. Clin Cancer Res (2008) 14:3840; 10. Chemphyschem (2008) 9:2019;

11. J Am Chem Soc (1994) 116:7801; 12. Electrophoresis (2003) 24:2348; 13. Biophys J (2007) 92:2162; 14. J Thromb

Haemost (2005) 3:2081; 15. Blood (2009) 113:1332; 16. Traffic (2007) 8:1179; 17. Chem Commun (Camb) (2010) 46:2926;

18. Anal Biochem (1997) 253:175; 19. Electrophoresis (2002) 23:81; 20. Anal Biochem (2002) 308:18; 21. J Gen Microbiol

(1993) 139:841; 22. Adv Photochem (1993) 18:315; 23. Photochem Photobiol (1983) 37:271; 24. J Am Chem Soc (1977)

99:4306; 25. J Cell Biol (1994) 126:901; 26. Biochem Biophys Res Commun (2005) 330:454; 27. Biochemistry (2002)

41:8630; 28. Biochemistry (1990) 29:8283; 29. Cytometry B Clin Cytom (2008) 74:244; 30. Clin Lab Haematol (2003)

25:373; 31. Br J Haematol (2004) 124:106; 32. Biophys J (1993) 65:113; 33. Biochemistry (1989) 28:2204; 34. J Biol Chem

(2006) 281:24036; 35. Biophys J (1998) 74:3093; 36. Biophys J (1998) 74:3083; 37. Biochemistry (1992) 31:12431; 38. ACS

Chem Biol (2010) 5:415; 39. Methods Mol Biol (2008) 491:213; 40. J Gen Physiol (2008) 132:209; 41. Biophys J (2007)

92:2403; 42. Bioconjug Chem (1998) 9:160; 43. Nat Struct Biol (2001) 8:540; 44. Biophys J (2001) 81:2851; 45. Nat Methods

(2010) 7:377; 46. Biochim Biophys Acta (2009) 1787:1499; 47. BMC Cell Biol (2007) 8:43; 48. Biochemistry (2005) 44:3694;

49. Proc Natl Acad Sci U S A (2006) 103:12619; 50. Anal Chem (1985) 57:1864; 51. Anal Chem (1983) 55:1786; 52. FEBS

Lett (1970) 6:346; 53. Arch Biochem Biophys (1990) 281:6; 54. Biochemistry (1990) 29:10613; 55. Biochemistry (1990)

29:7309; 56. J Biochem (Tokyo) (1990) 107:563; 57. Biochim Biophys Acta (1988) 956:217; 58. J Biol Chem (1991) 266:13777;

59. J Biol Chem (1983) 258:5419; 60. Anal Chim Acta (1994) 290:3; 61. Anal Chem (1984) 56:2461; 62. Chem Pharm Bull

(Tokyo) (1990) 38:2290; 63. J Chromatogr (1990) 514:189; 64. J Chromatogr (1990) 502:230; 65. Anal Biochem (2003)

314:166; 66. J Biol Inorg Chem (2006) 11:1049; 67. Proc Natl Acad Sci U S A (2001) 98:5556; 68. J Chromatogr A (1998)

798:47; 69. Techniques in Protein Chemistry V, Crabb JW, Ed. 1994 p. 189; 70. J Am Chem Soc (2009) 131:13286; 71. Nat

Methods (2010) 7:67; 72. J Biol Chem (1999) 274:6626; 73. Anal Bioanal Chem (2005) 381:1387; 74. Methods Enzymol

(2000) 327:565; 75. Science (1998) 281:269; 76. J Am Chem Soc (2002) 124:6063; 77. J Am Chem Soc (2009) 131:4613;

78. Nat Biotechnol (2005) 23:1308; 79. Mol Biol Cell (2009) 20:233; 80. Proc Natl Acad Sci U S A (2006) 103:17777; 81. Nat

Cell Biol (2007) 9:1057; 82. Science (2002) 296:503; 83. Mol Biol Cell (2004) 15:5616; 84. Methods Mol Biol (2009) 485:151;

85. PLoS Pathog (2008) 4:e1000015; 86. J Virol (2009) 83:2611; 87. Nat Methods (2008) 5:75; 88. J Virol (2005) 79:4055;

89. Appl Environ Microbiol (2010) 76:1241; 90. Chem Biol (2008) 15:619; 91. J Microsc (2009) 234:9; 92. Biotechniques

(2006) 41:569; 93. Proc Natl Acad Sci U S A (2003) 100:13308; 94. J Biol Chem (2008) 283:1501; 95. Biochemistry (2005)

44:16835; 96. J Biol Chem (2005) 280:2613; 97. Biochemistry (2005) 44:4312; 98. Biochemistry (2001) 40:1171; 99. Protein

Sci (2003) 12:1567; 100. Microsc Res Tech (1998) 42:2; 101. J Histochem Cytochem (2000) 48:471; 102. J Biol Chem (2000)

275:30458; 103. J Biol Chem (2000) 275:30465; 104. Nat Biotechnol (2001) 19:365.

DATA TABLE 2.2 THIOL-REACTIVE PROBES EXCITED WITH VISIBLE LIGHT