. 2014 May 15;9(5):e95137. doi: 10.1371/journal.pone.0095137

Table 1. Comparison of three different SBs with different surface chemistries.

	SB-Epoxy	SB-NH₂	SB-COOH
Sizes (diameter)	2.8 µm	2.8 µm	2.8 µm
Chemical formula of surfaces	Epoxy group	Amino group	Carboxylic acidgroup
Hydrophobicity ^*	More hydrophobic thanSB-COOH	More hydrophobic thanSB-COOH	Extremelyhydrophilic
Charge ^*	Slightly positive	Positive	Negative

*The hydrophobicity and surface charge of each SB were determined by a contact angle and zeta potential analysis, respectively. Information about SBs is available upon request from the authors (Dynal Biotech Technical Support, unpublished data).