Hi Vijaykumar, interesting project!

I don't know of a specific protocol, but my guess is that a way to do this is by dissolving the tape in an organic solvent and isolate the peptides by reverse-phase HPLC. 

There are many organic solvent systems that are used to separate peptides using RP-HPLC, you just have to find an organic solvent system that easily dissolves your tape and can be applied to HPLC to separate peptides.

Hi Vijaykumar, 

Try acetonitrile or isopropanol to attempt dissolving your proteins, and since they are used for gradient elution of proteins in HPLC, you might be successful without denaturing the proteins. 

Best of luck

From your question it is not clear which downstream processing will be done to those proteins. From my experience with very limited amount of precious biological samples, I would try first with a related sample that you do not need and I would start extraction from the tape by milder-to-harsher solvent or approaches. For example, start scraping the tape with addition of small volumes of PBS and rapidly put the material on ice. You may want to add a protease inhibitor cocktail to the PBS. Then if you have limited amounts of tissue and want to estimate total protein without losing sample, I recommend using nanodrop or similar device. Best of luck.

Dear All,

Many thanks for the suggestions. I will go ahead with isolating the proteins using different solvents and estimate the total protein.

Are you going to identify the proteins by mass spectrometry? If yes, you may digest the tape with trypsin without prior isolation

Yes, Mass spectroscopy is our first option. I will keep that in mind, however, is it still possible to quantify the proteins when digested with trypsin?

Hi Vijaykumar, Personally, I have some reservations on using proteinases to release peptides/proteins from an adhesive tape.

Proteinases, like trypsin, work great on soluble proteins/peptides. However, I foresee a problem using trypsin on surface bound proteins/peptides, especially if they are encased in adhesive compounds from your tape.

Hi Vijaykumar,

We have worked on this particular problem a few years back and had excellent results using high pressure extraction technique. Most adhesives would hold on tightly to keratinocytes, so the yields when tape pieces are just washed in solvents are pretty low. If scraped, adhesives would interfere with many downstream steps. Our method saturates hydrophobic adhesives and cells with water and causes the cells to fall off the tape in virtually any aqueous buffer. In addition, high pressure helps to hydrate and lyse the dry skin cells so you get a very high protein yield. Please check this application note online: 

http://www.pressurebiosciences.com/PrEP-files/SkinTape-PrEP.pdf

Moreover, trypsin and Lys-C digestion at high pressure is faster and yields more peptides. Therefore, it is possible that with the use of high pressure instrument you can combine extraction and digestion in one step for this application . 

Best,

Alex

Dear Alex,

thanks for your suggestion. I will have a look at the procedure. It sounds interesting.