I etertnarv Immunology and Immunopathologv 37 ( 1993 ) 61-71 61 Else, ler Science Pubhshers B V, Amsterdam Purification and characterization of IgG and IgG2 from buffalo (Bubalus bubalis) serum and colostrum N K Kakker and M C Goel lmmunologl Se~ tton Department o! ~ etermat )' Ml~ robtolog~ Hat vana 4gpt~ ultmal (~m) et sttl Htsar-125004 lndta ( Accepted 10 August 1992) ABSTRACT Kakker N K and Goel M C, 1993 Purification and characterization oflgG~ and IgG2 from buffalo (Bubalus bubah~ ) serum and colostrum Iet hnmunol hnmunopathol 37 61-71 Buffalo lgG~ and IgG2 were purified from serum and colostrum using salt preclp,tatlon, dial)sis gel filtration and ion-exchange chromatograph) Their purity was monitored b) lmmunodfffusLon and mlmunoelectrophoresis using antl-heav} chain specific sera and SDS-PAGE Selectl~ e binding ol IgG2 to protem-A was used to remo~e lgG2 from lgGl preparations The IgGt and IgG2 had a molec- ular mass (Mr) of 162 0 and 161 5 kD, respectively and were found to consist o! hea~) (H) and light ( L ) chains The H and L chains had Mr of 58 and 24 kD respect~ el~ Reductmn-alk~latlon followed by gel filtration was used for the ~solatlon of H and k chains While intact H chains were obtained the L chains appeared to be cleaved into 14 kD molecules and smaller fragments The mean hexoscs content of the serum lgG~ and IgGz was 1 81 ± 0 02% and 0 70 _+ 0 02% respectl~el~ The correspond- mg ~alues for colostral lgG~ and IgG~ were 1 76+0 01% and 0 78_+0 08% Both the IgG subclasses activated homologous complement These results suggest that buffalo and cattle IgG subclasses ha~ e man) common characteristics and minor differences ABBREVIATIONS C, complement, EA erythrocyte-antlbody, H, heavy, HA, haemagglutmation ID, ~mmunod~ffu- slon IE lmmunoelectrophoresls Igs lmmunoglobuhns L light 2-ME 2-mercaptoethanol INTRODUCTION The Immunoglobuhns (Igs) of cattle have been extensively investigated and reviewed (Butler, 1983, 1986), but not those of the water buffalo, an economically important species Buffaloes hke other ruminants, possess at least three classes of Igs, namely IgM, IgA and IgG with ~ts two subclasses, Correspondence to N K Kakker, Immunology Section, Department of Veterlnar~ M~croblol- og) Haryana Agricultural University, Hlsar-125004, India © 1993 Elsevier Science Publishers B V