Liquid chromatography (LC) can be used for preparative or analytical applications. There are fundamental differences between these two most common forms of LC, but few people tend to differentiate between them. Although used to achieve different goals, the two techniques are complementary and are often applied in parallel.
For example, analytical LC is often used to assess the purity and purification performed by preparative LC. Preparative applications are often initially performed at an analytical level and then scaled-up to the preparative scale. Having an LC purification system that enables this approach is beneficial to laboratory efficiency.
Considerations for analytical and preparative LC
Preparative workflows are used for obtaining the fractionation of groups of compounds, usually as a function of their polarity, for further use rather than analysis. Analytical LC is used to separate individual compounds and determines the existence and concentration of an analyte in a sample. Analytical LC is most commonly used in the pharmaceutical and manufacturing industries, as well as in medical and research labs. When looking for the most appropriate LC system for analytical methods, you should consider possible pump pressures, possible flow rates, stationary phase pore size (see Agilent’s InfinityLab Poroshell columns), and number of wavelength detectors. Preparative LC for mixture separation is widely deployed for quality analysis and control, and laboratory sample preparation. Interoperability with other equipment is an important consideration for many labs, as is the capacity for real-time computer analysis and control.
Efficient sample purification
There are three aspects of lab operational efficiency: purification efficiency, instrument efficiency, and laboratory efficiency. By using a wide range of detectors, including mass-based fraction-triggering, every compound can be purified and recovered. Using the right instrument is crucial for minimizing losses, and ensuring a scalable flowrate. Matching your purification workflow to the right solution through a tailored system can make all the difference, from analytical to preparative scale. Customizable purification solutions make it possible for labs to integrate their workflows in a neat space. Laboratory requirements change regularly, so it is important to implement a flexible, adaptable system to meet these needs consistently over time. The following diagram shows the range of possibilities available with Agilent InfinityLab LC Purification Solutions, for analytical, semipreparative, and preparative workflows. It shows how to make the right column and system choice based on your desired LC system and your productivity range.
Choosing the right column and supplies is essential to achieving maximum instrument uptime and minimizing laboratory costs.
Designing the right workflow
There are four important factors to consider when designing protein purification workflows:
- Sample integrity
- Sample purity
The relative importance of each depends on the application: absolute sample purity is essential for antibody production, for example, for therapeutic or diagnostic applications. Yield refers to preparative chromatography, where the desired outcome of the separation is purification of a protein for downstream applications. Sample integrity is also important for such workflows, for example protein must be correctly folded to be evaluated in vitro.
Triple the efficiency for your lab
Agilent InfinityLab LC Purification Systems address the needs of scientists performing analytical, preparative or semipreparative LC, or a combination of the three. For analytical-scale LC, Agilent offers the 1220, 1260, and 1290 Infinity II LCs, each providing labs with unique high-performance separation with superior analytical efficiency, instrument efficiency, and laboratory efficiency.
With the highest affordability, the 1220 Infinity II LC provides robust and highly reliable LC quality, giving you confidence in your results. The 1260 Infinity II platform gives the broadest instrument choice, matching with the latest column technologies to guarantee robust separation and detection performance. The laboratory efficiency of the 1290 Infinity II LC provides the highest sample capacity and fastest injection cycles, combined with a new degree of usability, for the highest throughput for any application.
The two preparative systems from Agilent, the 1260 Infinity II and the 1290 Infinity II, enable users to obtain the highest levels of purity and recovery. The 1290 Infinity II LC provides optimum flexibility in fraction size while maintaining high-precision recovery by combining UV and mass-based peak identification. Agilent automated purification software supports automated transfer from analytical to preparative-scale chromatography, offering the option for full workflow automation. For more information on the Agilent InfinityLab LC Purification Solutions, please visit https://www.agilent.com/en/products/liquid-chromatography/infinitylab-lc-purification-solutions or download the brochure here.