Hello colleagues,
As I started work with MALDI-TOF MS I wondering if it is possible to prepare and conserve MALDI slides for later uses, without read it immediately after the preparation.
Specifically my concern is with use and conservation of prepared slides with bacteria, fungi and yeasts, using CHCA as matrix.
I searched some literature around without results, so someone have experiences with the conservation of a prepared slide or some protocol currently in use.
Thank you
Hi Manlio: I always prepared MALDI slides ahead of time to save my time with actual machine use, and found it convenient. Digested and purified peptides were quite stable in crystal form with matrix. Normally, I put the prepared slide/plate in a petri dish to protect it from being scratched or wiped out accidentally. Read our paper in PMID:
9278435.
Hi Ke-Wei, do you leave the dish at ambient temperature?And for how much time.
My question arise because when I do PMF with bacteria or yeast and prepare the slide before fime (say the afternoon for the next morning) about half the times the reading don't make much sense. I don't exclude errors somewhere in the process but it happens quite often.
My samples were purified by HPLC, but were still shown poor signals some time. It might be the impurities in your sample that caused inconsistency in fresh vs old slides.
That's entirely possible, moreso because my samples are from colonies on agar, usually. In my case isn't impurities but mostly extracellular matrix interferences, I guess.
Hi Manlio,
The matrix of your choice, CHCA is light sensitive. Therefore, it will be important to keep your slides in a dark environment, in order to preserve the integrity of the co-crystallized product..
Sorry for the delay in response, hope this is useful.
Thank you Hediye. Never thought about that.
Where I could found informations about the various matrixes stability?
Hi Manlio,
Here is the product document from Sigma-Aldrich where it is recommended that for storage stability, the matrix is to be protected from light. Also, in the "preparation of MALDI matrices, they recommend that matrix solution to be stored in dark and stored for a week...
We always received any of the already constituted matrix in dark bottles. Once the peptides were mixed with the matrix, we would place the mass spec targets in their original containers, cover them with foil and keep them in drawers, away from direct light.
Thank you again.
I could only add we store the prepared matrix in fridge (about 4°C ) when not used for long and in the late afternoon/niight when no one use it, this is useful in reducing the evaporation of ACN and the concentration of the solution.
Hi Manlio,
That sounds like a good practice. Fridge is dark and keeps the matrix solution in stable form. Our pre-made matrices were also stored in dark bottles and in the refrigerator.
- Badges
- Science method
- Similar topics
- Chemistry
- General Biochemistry
- Biochemical Methods