System suitability method for use with protein concentration determination by slope

1. A method of determining the suitability of a variable-length spectrophotometer for determining protein concentration of a protein sample, comprising measuring the absorbance of Patent Blue dye (PBD) or AMG Blue Dye (ABD) at least two wavelengths, the first wavelength of 280 nm and the subsequent wavelength(s) selected from the group consisting of 310 nm, 412 nm, 510 nm and 615 nm.

2. The method of claim 1 , wherein at least a third wavelength is used, wherein the third wavelength is different than the second wavelength and selected from the group consisting of 310 nm, 412 nm, 510 nm and 615 nm.

3. The method of claim 2 , wherein the variable-length spectrophotometer is considered suitable if the absorbance readings of the PBD or ABD are equal to or less than 10% of those values supplied in a certificate of analysis supplied with the PBD or ABD.

4. The method of claim 1 , wherein the PBD or ABD is measured three times for each wavelength before measuring the protein concentration of the protein sample, and wherein the PBD or ABD is measured three times for each wavelength after measuring the protein concentration of the protein samples.

5. The method of claim 1 , wherein the first wavelength is 280 nm and the second wavelength is 310 nm.

6. The method of claim 1 , wherein the variable-length spectrophotometer or fixed path length spectrophotometer is considered suitable if the absorbance readings of the PBD or ABD are at least equal to or less than 5% of those supplied in a certificate of analysis supplied with the PBD or ABD.

7. The method of claim 1 , wherein the readings have a relative standard deviation (RSD) percentage of ≤5%.

8. The method of claim 1 , wherein the protein sample comprises a therapeutic protein.

9. The method of claim 8 , wherein the therapeutic polypeptide is selected from the group consisting of infliximab, bevacizumab, cetuximab, ranibizumab, palivizumab, abagovomab, abciximab, actoxumab, adalimumab, afelimomab, afutuzumab, alacizumab, alacizumab pegol, ald518, alemtuzumab, alirocumab, altumomab, amatuximab, anatumomab mafenatox, anrukinzumab, apolizumab, arcitumomab, aselizumab, altinumab, atlizumab, atorolimiumab, tocilizumab, bapineuzumab, basiliximab, bavituximab, bectumomab, belimumab, benralizumab, bertilimumab, besilesomab, bevacizumab, bezlotoxumab, biciromab, bivatuzumab, bivatuzumab mertansine, blinatumomab, blosozumab, brentuximab vedotin, briakinumab, brodalumab, canakinumab, cantuzumab mertansine, cantuzumab mertansine, caplacizumab, capromab pendetide, carlumab, catumaxomab, cc49, cedelizumab, certolizumab pegol, cetuximab, citatuzumab bogatox, cixutumumab, clazakizumab, clenoliximab, clivatuzumab tetraxetan, conatumumab, crenezumab, cr6261, dacetuzumab, daclizumab, dalotuzumab, daratumumab, demcizumab, denosumab, detumomab, dorlimomab aritox, drozitumab, duligotumab, dupilumab, ecromeximab, eculizumab, edobacomab, edrecolomab, efalizumab, efungumab, elotuzumab, elsilimomab, enavatuzumab, enlimomab pegol, enokizumab, enoticumab, ensituximab, epitumomab cituxetan, epratuzumab, erenumab, erlizumab, ertumaxomab, etaracizumab, etrolizumab, evolocumab, exbivirumab, fanolesomab, faralimomab, farletuzumab, fasinumab, fbta05, felvizumab, fezakinumab, ficlatuzumab, figitumumab, flanvotumab, fontolizumab, foralumab, foravirumab, fresolimumab, fulranumab, futuximab, galiximab, ganitumab, gantenerumab, gavilimomab, gemtuzumab ozogamicin, gevokizumab, girentuximab, glembatumumab vedotin, golimumab, gomiliximab, gs6624, ibalizumab, ibritumomab tiuxetan, icrucumab, igovomab, imciromab, imgatuzumab, inclacumab, indatuximab ravtansine, infliximab, intetumumab, inolimomab, inotuzumab ozogamicin, ipilimumab, iratumumab, itolizumab, ixekizumab, keliximab, labetuzumab, lebrikizumab, lemalesomab, lerdelimumab, lexatumumab, libivirumab, ligelizumab, lintuzumab, lirilumab, lorvotuzumab mertansine, lucatumumab, lumiliximab, mapatumumab, maslimomab, mavrilimumab, matuzumab, mepolizumab, metelimumab, milatuzumab, minretumomab, mitumomab, mogamulizumab, morolimumab, motavizumab, moxetumomab pasudotox, muromonab-cd3, nacolomab tafenatox, namilumab, naptumomab estafenatox, narnatumab, natalizumab, nebacumab, necitumumab, nerelimomab, nesvacumab, nimotuzumab, nivolumab, nofetumomab merpentan, ocaratuzumab, ocrelizumab, odulimomab, ofatumumab, olaratumab, olokizumab, omalizumab, onartuzumab, oportuzumab monatox, oregovomab, orticumab, otelixizumab, oxelumab, ozanezumab, ozoralizumab, pagibaximab, palivizumab, panitumumab, panobacumab, parsatuzumab, pascolizumab, pateclizumab, patritumab, pemtumomab, perakizumab, pertuzumab, pexelizumab, pidilizumab, pintumomab, placulumab, ponezumab, priliximab, pritumumab, PRO 140, quilizumab, racotumomab, radretumab, rafivirumab, ramucirumab, ranibizumab, raxibacumab, regavirumab, reslizumab, rilotumumab, rituximab, robatumumab, roledumab, romosozumab, rontalizumab, rovelizumab, ruplizumab, samalizumab, sarilumab, satumomab pendetide, secukinumab, sevirumab, sibrotuzumab, sifalimumab, siltuximab, simtuzumab, siplizumab, sirukumab, solanezumab, solitomab, sonepcizumab, sontuzumab, stamulumab, sulesomab, suvizumab, tabalumab, tacatuzumab tetraxetan, tadocizumab, talizumab, tanezumab, taplitumomab paptox, tefibazumab, telimomab aritox, tenatumomab, tefibazumab, teneliximab, teplizumab, teprotumumab, tezepelumab, TGN1412, tremelimumab, ticilimumab, tildrakizumab, tigatuzumab, TNX-650, tocilizumab, toralizumab, tositumomab, tralokinumab, trastuzumab, TRBS07, tregalizumab, tucotuzumab celmoleukin, tuvirumab, ublituximab, urelumab, urtoxazumab, ustekinumab, vapaliximab, vatelizumab, vedolizumab, veltuzumab, vepalimomab, vesencumab, visilizumab, volociximab, vorsetuzumab mafodotin, votumumab, zalutumumab, zanolimumab, zatuximab, ziralimumab, zolimomab aritox, a glycoprotein, CD polypeptide, a HER receptor polypeptide, a cell adhesion polypeptide, a growth factor polypeptide, an insulin polypeptide, an insulin-related polypeptide, a coagulation polypeptide, a coagulation-related polypeptide, albumin, IgE, a blood group antigen, a colony stimulating factor, a receptor, a neurotrophic factor, an interferon, an interleukin, a viral antigen, a lipoprotein, calcitonin, glucagon, atrial natriuretic factor, lung surfactant, tumor necrosis factor-alpha and -beta, enkephalinase, mouse gonadotropin-associated peptide, DNAse, inhibin, activing, an integrin, protein A, protein D, a rheumatoid factor, an immunotoxin, a bone morphogenetic protein, a superoxide dismutase, a surface membrane polypeptide, a decay accelerating factor, an AIDS envelope, a transport polypeptide, a homing receptor, an addressin, a regulatory polypeptide, an immunoadhesin, a myostatin, a TALL polypeptide, an amyloid polypeptide, a thymic stromal lymphopoietin, a RANK ligand, a c-kit polypeptide, a TNF receptor, and an angiopoietin, the antibodies shown in Table 1 and biologically active fragments, analogs or variants thereof.

10. The method of claim 1 , wherein the protein sample comprises an antigen binding protein, an antibody, a bi-specific antibody, a tri-specific antibody, a BiTE molecule, or a fragment or derivative thereof.

11. The method of claim 1 , wherein the variable length spectrophotometer is a SoloVPE spectrophotometer (C Technologies, Inc.; Bridgewater, NJ).

12. A method of determining the suitability of a fixed path length spectrophotometer for determining protein concentration of a protein sample, comprising measuring the absorbance of ABD at least two wavelengths, the first wavelength of 280 nm and the subsequent wavelength(s) selected from the group consisting of 310 nm, 412 nm, 510 nm and 615 nm.

13. The method of claim 12 , wherein at least a third wavelength is used, wherein the third wavelength is different than the second wavelength and selected from the group consisting of 310 nm, 412 nm, 510 nm and 615 nm.

14. The method of claim 12 , wherein the PBD or ABD is measured three times for each wavelength before measuring the protein concentration of the protein sample, and wherein the PBD or ABD is measured three times for each wavelength after measuring the protein concentration of the protein samples.

15. The method of claim 12 , wherein the first wavelength is 280 nm and the second wavelength is 310 nm.

16. The method of claim 12 , wherein the variable-length spectrophotometer or fixed path length spectrophotometer is considered suitable if the absorbance readings of the PBD or ABD are at least equal to or less than 5% of those supplied in a certificate of analysis supplied with the PBD or ABD.

17. The method of claim 12 , wherein the protein sample comprises a therapeutic protein.