Hi Dusan, Thank you for your response. Can you also tell me...

Hi Theodora, Thank you for your interest in our protocol! So, DMA/DHB matrix is by far the best MALDI matrix for carbohydrates (sugars and oligossacharides). You can find publication from our lab about this: http://onlinelibrary.wiley.com/doi/10.1002/rcm.5060/abstract There is theory that DMA mimics Schiff base formation with sugars which increase their sensitivity during ionization: http://onlinelibrary.wiley.com/doi/10.1002/rcm.3265/abstract For your second question, I usually scan sample before application of matrix. In this particular case I didn't stain it, but in fact you can stain it after finishing your MALDI run: wash matrix with 70% EtOH (by dipping plate in 70%EtOH solution 3x2min) and then you can stain it. Or you can stain consecutive section if this washing doesn't give you good results. For your stems: I did analyze long time ago xylans from maize stem: be aware that you need to know general chemical organization and polyssacharides composition. For example I did remember that these xylans in maize stem are very very rich in acetylation and feruliation so I needed to remove these decorations by KOH treatment before application of enzymes (since these decorations will hide glycosidic bond that enzyme recognizes). I hope this will guide your experiments. Feel free to contact me if you need further assistance. Dusan