There are four differences between the Fe-NTA kit (Cat. No. 88300) and the new High-Select Fe-NTA kit (Cat. No. A32992) kit as follows:
1. The selectivity - the ratio of number of phosphopeptides over total peptides - was significantly improved to 99% with Cat. No. A32992, because the reagents were extensively optimized for the phosphopeptide selection.
2. The phosphopeptide yield was also increased to 33 µg based on quantitative colorimetric peptide assay (Cat. No. 23275).
3. The reagent is a pre-formulated format, so mixing reagent to prepare the working solution from stock solutions provided in the old kit (Cat. No. 88300) is not necessary, so it is easier to handle.
4. The enrichment protocol is optimized and streamlined, which means there are many fewer steps than with Cat. No. 88300. Thus, it takes <45 min to finish the entire protocol compared to 2 hours with the old kit (Cat. No. 88300).
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