Simple question on LC and MS - (Jan/29/2010 )
I have to do a quick compare and contrast of protein identification techniques and I'm unsure of 2 necessary pieces of information due to lack of experience.
1)How long approximately does it take to prepare and run a liquid chromatography sample?
2)How long approximately does it take to prepare and run a mass spec sample (MALDI or ES)?
3)Are the components needed to run them expensive?
HPLC sample preparations can be short (run directly) for some methods like size exclusion, or longer (perform extraction or perform sample derivatives--a few hours). It all depends on the method. I ran two peptide digestion methods that were similar to the LC/MS method (but could be considered "normal HPLC") for a protein of interest. We did protein digestions overnight, but the sample prep was very short. 5 minutes at the most. Run times for LC can be short (10 minutes is the shortest I've seen) to long (70 minutes). The peptide method I ran had a run time of 2.5 hrs which is also similar to the LC/MS method.
In general (or on average) LC/MS run times will be longer since you need to resolve many tiny little peaks.
Yes components are expensive for both. I believe typical LC system can be ~$50,000. I don't have a price for LCMS, but it was so pricey that our large company had to have a few months of backlogged work on the LCMS to justify the purchase of a second one (where as we had hundreds of HPLC systems
All I can really add is that the mass spec is the expensive part. An HPLC system isn't so expensive.