The sequence analysis of a peptide solution sample is usually performed using a polybrene-processed glass fiber disk as the sample support. With a PVDF membrane, because the holding power for peptide samples is relatively small, satisfactory results may not be obtained by simply loading the sample in the same way that protein samples are loaded. The sequence analysis of a peptide sample is possible, however, using the following procedure.
1. Immerse a PVDF membrane cut to a size that fits into the PPSQ reactor in methanol.
2. Set the PVDF membrane in the reactor and load the sample.
3. Dry the sample (for approximately 10 minutes).
4. Prepare the following polybrene solution.
Polybrene solution: 20μL
0.1% TFA(Trifluoro acetic acid): 10μL
Methanol: 70μL
Total: 100μL
NOTE: This solution cannot be stored. Prepare it only when it is required.
5. Load 10μL of the solution to the PVDF membrane and dry it for 10 minutes in the reactor.
6. Assemble the reactor and perform standard (PVDF) sequence analysis.
In the first cycle, peaks caused by the polybrene may appear.