Synteza analogow nukleozydów i nukleozydów modyfikowanych. synteza i badanie struktury oligonukleotydów, zawierających jednostki modyfikowane. Znakowanie nukleozydow izotopami ²H, ¹³C, ¹⁵N.
Badanie fotofizyczne składników kwasów nukleinowych i oligonukleotydów. Spektroskopia NMR oligonukleotydów, badania wlaściwości kompleksujących.

• The first example of sequence-specific non-uniformly ¹³C-labelled RNA: Synthesis of the 29mer HIV-1 TAR RNA with ¹³C relaxation window” J. Milecki, E. Zamaratski. T.V. Maltseva, A. Földesi, R.W. Adamiak, J. Chattopadhyaya, Tetrahedron, 55, 6603-6622 (1999)


• An NMR conformational study of the complexes of ¹³C/²H double-labelled 2’-deoxynucleosides and deoxycytidine kinase (dCK)” T. Maltseva, E. Usova, S. Eriksson, J. Milecki, A. Földesi and J. Chattopadhyaya J. Chem. Soc. Perkin II , 2199-2207 (2000)


• „The 1.19 A X-ray Structure of 2'-O-Me(CGCGCG)2 Duplex Shows Dehydrated RNA with 2-Methyl-2,4-pentanediol in the Minor Groove”, D.A. Adamiak, W.R. Rypniewski, J.Milecki, R.W. Adamiak, Nucleic Acids Res. 29, 4144-4153 (2001)


• „Specific labelling of nucleosides and nucleotides with ¹³C and ¹⁵N”, Jan Milecki, J. Labelled Comp. Radiopharm. 45, 307-337 (2002)


• „NMR spectra of the tautomeric mixture of two forms of 6-azidopurine ribonucleoside labeled with ¹⁵N” Anna Masternak, Bogdan Skalski, Jan Milecki*, J. Labelled Comp. Radiopharm. 50, 43-46, (2007)


• “Polyether-functionalysed Uridine as an ion receptor” Jan Milecki, Grzegorz Schroeder, Mendeleev Commun. 17¸ 22-24 (2007)


• „Noncanonical G(syn)-G(anti) base pairts stabilized by sulphate anions in two X-ray structures of the (GUGGUCUGAUGAGGCC) RNA Duplex “ W. Rypniewski, D. Adamiak, R.W. Adamiak, J. Milecki, RNA, 14, 1845-1851 (2008)


• “Synthesis of an acyclic nucleoside analog of highly fluoresccent luminarosine” Joanna Nowak, Bohdan Skalski, Zofia Gdaniec, Jan Milecki Tetrahedron Letters, 50, 1671-1673 (2009)


• “The hydration and unusual hydrogen bonding in the crystal structure of an RNA duplex containing alterneting CG base pairs” Dorota Adamiak, Jan Milecki, Ryszard W. Adamiak, Wojciech Rypniewski New J. Chem. accepted