Surface Chemistry and Stability
The primary distinction between RSA-Pro™ and RSA-Pro X™ vials lies in the type of surface treatment applied to the RSA™ glass and the resulting hydrolytic stability of each.
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RSA-Pro™ utilizes a vapor-phase deposition process in which silane-based materials are ionically bonded to the glass surface. This treatment imparts hydrophobicity but is not hydrolytically stable. As a result, RSA-Pro™ vials:
- Are not suitable for autoclaving or freezing
- May lose their hydrophobic properties over time, especially in aqueous environments
- Are available only as custom order items
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RSA-Pro X™, by contrast, employs a proprietary surface modification process that covalently bonds hydrophobic materials directly to the RSA™ glass surface. This results in:
- Exceptional hydrolytic stability, even with prolonged exposure to water
- Compatibility with autoclaving, freezing, and freeze-thaw cycles
- Long-term retention of hydrophobicity—stable for years under standard laboratory conditions
Summary of Key Differences
| Feature | RSA-Pro™ | RSA-Pro X™ |
|---|---|---|
| Surface Bond Type | Ionic | Covalent |
| Hydrophobicity | Moderate | High |
| Hydrolytic Stability | Low | Very High |
| Autoclave Compatible | No | Yes |
| Freeze/Thaw Compatible | No | Yes |
| Availability | Custom Order Only | Standard Product |
| Long-Term Performance | Degrades in aqueous conditions | Stable for years in aqueous media |
Recommendation
For applications involving aqueous solutions, long-term storage, or hydrophobic analytes such as proteins, peptides, and enzymes, RSA-Pro X™ is the preferred choice. Its robust surface chemistry ensures consistent performance and minimal analyte loss over time.
