Natraj Ram, Ph.D.

Publications

Papers and presentations

1. 2023
   Evaluation of the Design, Development, and Performance of a Mass-Flow Based, Open-Source Buffer Manufacturing System

   Ram N, Johnson J, Ardeshna H, Camire J, Campbell R, Chau D , et al.

   PDA Journal of Pharmaceutical Science and Technology 77(2):79–98

   DOI 10.5731/pdajpst.2021.012660PubMed 35987520

2. 2016
   Kinetic physico-chemical model for cell culture processes – applications and opportunities

   Ram N, Subramanian K, Ponzo J

   Cell Culture Engineering XV · Engineering Conferences International (ECI) · La Quinta, California, May 8–13, 2016

   Conference presentation Abstract (PDF)Conference archive

3. 2015
   Effect of cleaning agents and additives on Protein A ligand degradation and chromatography performance

   Yang L, Harding JD, Ivanov AV, Ramasubramanyan N, Dong DD

   Journal of Chromatography A 1385:63–68

   DOI 10.1016/j.chroma.2015.01.068PubMed 25680549

4. 2010
   Application of arginine as an efficient eluent in cation exchange chromatographic purification of a PEGylated peptide

   Annathur GV, Buckley JJ, Muthurania K, Ramasubramanyan N

   Journal of Chromatography A 1217(24):3783–3793

   DOI 10.1016/j.chroma.2010.04.019PubMed 20447639

5. 2009
   Binding and elution behavior of proteins on strong cation exchangers

   Pabst TM, Suda EJ, Thomas KE, Mensah P, Ramasubramanyan N, Gustafson ME , et al.

   Journal of Chromatography A 1216(45):7950–7956

   DOI 10.1016/j.chroma.2009.09.040PubMed 19815222

6. 2009
   Comparison of agarose and dextran-grafted agarose strong ion exchangers for the separation of protein aggregates

   Suda EJ, Thomas KE, Pabst TM, Mensah P, Ramasubramanyan N, Gustafson ME , et al.

   Journal of Chromatography A 1216(27):5256–5264

   DOI 10.1016/j.chroma.2009.05.021PubMed 19497581

7. 2008
   Separation of protein charge variants with induced pH gradients using anion exchange chromatographic columns

   Pabst TM, Carta G, Ramasubramanyan N, Hunter AK, Mensah P, Gustafson ME

   Biotechnology Progress 24(5):1096–1106

   DOI 10.1002/btpr.53PubMed 19194919

8. 2008
   Protein separations with induced pH gradients using cation-exchange chromatographic columns containing weak acid groups

   Pabst TM, Antos D, Carta G, Ramasubramanyan N, Hunter AK

   Journal of Chromatography A 1181(1–2):83–94

   DOI 10.1016/j.chroma.2007.12.054PubMed 18194806

9. 2007
   Impact of denaturation with urea on recombinant apolipoprotein A-I Milano ion-exchange adsorption: Equilibrium uptake behavior and protein mass transfer kinetics

   Hunter AK, Suda EJ, Das TK, Shell RE, Herberg JT, Ramasubramanyan N , et al.

   Biotechnology Journal 2(1):110–120

   DOI 10.1002/biot.200600165PubMed 17136731

10. 2007
    Comparison of strong anion-exchangers for the purification of a PEGylated protein

    Pabst TM, Buckley JJ, Ramasubramanyan N, Hunter AK

    Journal of Chromatography A 1147(2):172–182

    DOI 10.1016/j.chroma.2007.02.051PubMed 17346720

11. 2001
    Purification of Recombinant Green Fluorescent Protein Using Chromatofocusing with a pH Gradient Composed of Multiple Stepwise Fronts

    Narahari CR, Randers-Eichhorn L, Strong JC, Ramasubramanyan N, Rao G, Frey DD

    Biotechnology Progress 17(1):150–160

    DOI 10.1021/bp0001415PubMed 11170493

12. 1999
    Low cost phase-modulation measurements of nanosecond fluorescence lifetimes using a lock-in amplifier

    Harms P, Sipior J, Ram N, Carter GM, Rao G

    Review of Scientific Instruments 70(2):1535–1539

    DOI 10.1063/1.1149620

Inventor

Patents

Grouped by invention, newest first. Each number opens the patent on Google Patents; filings in other countries are listed there too.

1. 2024

   Systems and methods for biomolecule collection and isolation

   Life Technologies Corporation · first filed 2024

   Published application: US 2025/0289847 A1

2. 2013

   Low acidic species compositions and methods for producing and using the same

   AbbVie · first filed 2013

   Granted: US 9,085,618 B2 US 9,200,069 B2 US 9,200,070 B2 US 9,266,949 B2 US 9,315,574 B2 US 9,522,953 B2 AU 2013384204 B2 CA 2,899,308 C

3. 2013

   Purification of proteins using hydrophobic interaction chromatography

   AbbVie · first filed 2013

   Granted: US 8,946,395 B1

4. 2012

   Purification of antibodies using hydrophobic interaction chromatography

   AbbVie · first filed 2012

   Granted: US 9,249,182 B2

5. 2012

   Protein purification methods to reduce acidic species

   AbbVie · first filed 2012

   Granted: US 9,346,879 B2 US 9,957,318 B2 US 9,334,319 B2

6. 2011

   An integrated approach to the isolation and purification of antibodies

   Abbott Laboratories, now AbbVie · first filed 2011

   Published application: US 2012/0238730 A1 WO 2012/125735 A1

7. 2010

   Raman spectroscopy for bioprocess operations

   Abbott Laboratories, now AbbVie · first filed 2010

   Published application: US 2012/0123688 A1 WO 2012/037430 A1

8. 2010

   Highly sensitive monoclonal antibody residual detection assay

   Abbott Laboratories, now AbbVie · first filed 2010

   Granted: US 8,945,860 B2

9. 1999

   Methods of DNA purification and purified DNA

   Cambrex Bio Science Baltimore, later Lonza Biologics · first filed 1999

   Granted: US 6,953,686 B1 EP 1 187 840 B1 AU 782153 B2 CA 2,375,215 C