General Factors To Consider When Choosing Your Syringe Material Type
In designing your experiment and setting up your syringe pump, it is important to choose the correct syringe material type for your application. Chemyx syringe pumps support a wide variety of syringes and its versatile software enables the user to quickly and efficiently select a syringe from the syringe library, which lists syringes by the manufacturer. Alternatively, users can manually input the physical characteristics of the syringe. When choosing a syringe type for your experiments, it is important to consider whether the syringe is chemically compatible with your sample. Other important considerations are syringe cost and durability. The physicochemical characteristics of a syringe are mostly dictated by their material of construction. Commercially available syringes are typically made of glass, polymer (plastic) or stainless steel.
Here are some of the advantages and disadvantages of glass, plastic and stainless steel syringe material types.
Glass syringes are the most widely used in syringe pump applications. They are available in a variety of sizes including microliter volumes, enabling experiments with extremely small injection volumes. They generally have small volume errors (typically ~1%) and are thus ideal for high precision work. Additionally, glass syringes have a high gas barrier, which is good for oxygen-sensitive applications 1.
However, there are some negatives associated with glass syringes. Glass is susceptible to breakage. Chemical interaction between the sample and glass can lead to delamination, whereby the glass corrodes or flakes 2. Also, due to their material of construction and manufacturing process, glass syringes can sometimes contaminate samples with sodium, heavy metals and/or tungsten 1. This can be of particular concern if your samples contain demetallated (or apo) proteins. Contamination can also originate from adhesives, silicon oil and elastomer components that are typically added to glass syringes 1. These contaminants can significantly influence your experiments, particularly when working with sensitive biological samples and proteins. For example, silicon oil lubricated glass syringes have been found to increase protein loss in biological samples through the formation of insoluble aggregates3.
Plastic syringes have become a popular choice in recent years. They are cheaper and more durable than glass syringes, are typically free from heavy metals and tungsten and have little to no siliconization1. However, plastic syringes have a lower gas barrier compared to glass syringes and thus, may not be suitable if you are working with degassed samples and/or samples that are very sensitive to oxygen. Additionally, plastic syringes can become discolored and hazy upon repeated sterilization . Although plastic syringes are widely available in a variety of sizes, they are generally not available in small microliter sizes. Furthermore, the injection volumes of plastic syringes can have errors as large as ±5%, which is higher than for glass syringes.
Stainless Steel Syringes
If you are using high flow rates and viscous samples, you are likely to encounter high syringe pressures. In these cases, you may require a stainless steel syringe. Stainless steel syringes are extremely durable, have low volume errors and high chemical resistance. However, these syringes can be harder to load than glass or plastic syringes because it is not possible to visually detect air bubbles; additionally, you cannot monitor samples for precipitation during the course of the experiment. Stainless steel syringes are generally more expensive than glass and plastic syringes and are typically only available in larger volumes. For these reasons, stainless steel syringes are normally only used in high-pressure applications.
In preparing to use your syringe pump, it is important to choose the correct syringe material type. Syringes are typically available in glass, plastic and stainless steel. Glass syringes are most common; they are available in a variety of sizes including in the microliter range, are great for oxygen sensitive samples and have low volume errors. However, glass syringes can break and they can sometimes contaminate your samples with metals, adhesives, silicon oil and elastomer components. Plastic syringes are cheaper than glass syringes and have less potential contaminants. However, they are less suitable for oxygen sensitive samples and can become discolored upon repeated sterilization. Furthermore, plastic syringes have larger volume errors. Stainless steel syringes have high chemical resistance and low volume errors and are ideal for high-pressure applications because of their durability. However, they are more expensive, are only available in larger sizes and can be more difficult to use because they are not transparent. Users should consider all factors when choosing their syringe material type, including the chemical composition of the sample, implications of contamination, desired injection volumes, and anticipated experimental pressures.
- A. Busimi, “A tale of two materials: What the glass vs. polymer,” 22 April 2015. [Online]. Available: http://blog.us.schott.com/a-tale-of-two-materials-what-the-glass-vs-polymer-debate-really-means/.
- European Pharmaceutical Manufacturer, “The glass ceiling: The advantages of polymers over glass in biologic drug delivery,” 23 September 2016. [Online]. Available: https://www.epmmagazine.com/opinion/the-glass-ceiling-the-advantages-of-polymers-over-glass-in-b/.
- K. T. S. U. K. F. Elena Krayukhina, “Effects of Syringe Material and Silicone Oil Lubrication on the Stability of Pharmaceutical Proteins,”Pharmaceutical Biotechnology, pp. 527-535, 2014.