KRATOS recently advertised the use of nor-harmane as a matrix for
oligonucleotides. They say that it negates the need for oligo salt removal
step prior to MALDI because nor-harmane minimize the formation of adduct
ions. Can you or anyone tell me more, composition, etc., please. I have
faxed to KRATOS and the information has not yet arrived.
Thanks!
Tony
At 08:39 AM 6/16/99 -0700, ABRF wrote:
>At 2:14 AM -0700 6/16/99, Ulf Hellman wrote:
>>Dear MALDI users!
>>Can anyone please suggest a robust procedure for MALDI analysis of
>>oligonucleotides and similar components. Type of matrix, type of modes
>>(lin/refl, pos/neg, etc) in the instrument, sample pretreatment, solvents
>>and whatever might be relevant? Realistic concentration of analyte?
>>Thanks in advance. /Ulf
>>******************************************************
>>Ulf,
>6-aza-2-thiothymine: Lecchi, P. et al. Nucl. Acids Res. 23, 1276-1277 (1995)
>
>3-hydroxypicolinic acid: Talbo, G. and Mann, M. Rapid Commun. Mass Spectr.
>10, 100-103 (1996)
>
>2,4,6-trihydroxyacetophenone: Pieles et al. Nucl. Acids Res. 21, 3191-3196
>(1993).
>
>2,3,4-trihydroxyacetophenone: Zhu et al. Rapid Commun. Mass Spectr. 10,
>383-388 (1996).
>
>Each of the above matrices has its own formulation and you will either have
>to get the original papers, or send me your FAX No. and I will FAX our
>worksheet on "how to do it".
>I have found 3-HPA is good for oligos, 5 kDa and larger. The matrix we have
>has sodium and potassium present which gives some headaches.
>6-aza is good for oligos up to 5 kDa and shows little adduction of metal
>ions or matrix. You can pretreat the sample with a few beads of cation
>exchanger which you make as the ammonium form, or use some other means of
>rigourously desalting the oligos. We run both reflector and linear DE modes
>in negative ion mode, 20 KV. Your oligo should be from several hundred
>femtomoles to about 1 pmole depending on MW and purity.
>Best regards,
>Gary
>
>Gary M. Hathaway
>Director, Protein Analytical Lab
>Caltech, 139-74
>400 S. Wilson Ave.
>Pasadena, CA 91125
>hathaway@cco.caltech.edu
>
>
************************************
Dr. Anthony T. Yeung, Ph.D.
Director, Fannie E. Rippel Biotechnology Facility
Member, Institute for Cancer Research
Fox Chase Cancer Center
7701 Burholme Ave. Philadelphia, PA 19111
Voice: 215-728-2488
FAX: 215-728-3647
email: AT_Yeung@FCCC.edu
http://www.fccc.edu/research/labs/yeung/
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