Peter M Kilby, Roche Discovery Welwyn, 40 Broadwater Road, Welwyn Garden City, Herts, AL7 3AY, UK. Current Address: Analytical Sciences, Syngenta, Jealotts Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK
I report the use of the Bio-Rad PROTEAN Plus Dodeca cell (Figure 1) for running 2-D SDS-PAGE slab gels with preparative protein loads. The Dodeca cell was used to run up to 11 vertical 916% gradient SDS-PAGE gels. Comparison of the gel images revealed a particularly wellresolved and reproducible set of second-dimension gels with very little smearing or streaking associated with any spots.
In proteome analysis it is crucially important to be able to run reproducible 2-D gels. Such is the importance of running high-quality gels for image analysis that many scientists have settled on performing two separate procedures in order to seek and identify protein expression changes. The first procedure involves running a set of gels with a low amount of protein loaded and using these gels for image analysis. The second procedure requires running additional gels with a much larger amount of protein for protein identification purposes (Grg et al. 2000). This practice has two main disadvantages: first, more gels must be run, and second, due to the poorer quality of heavily loaded gels, it is more difficult to be sure of selecting the correct spot for protein identification. At Roche Welwyn, I have taken the approach of working with more heavily loaded gels and using these gels for both image analysis and protein identification.
I regularly use the Bio-Rad PROTEAN II xi cel