Purifikasi Imunoglobulin G (IgG) Spesifik African Swine Fever (ASF) dari Plasma Konvalesen dan Serum Babi

Abstract

African swine fever (ASF) merupakan penyakit viral pada babi dengan tingkat kematian tinggi sehingga diperlukan antibodi spesifik untuk mendukung pengembangan antigen pada penelitian lanjutan. Penelitian ini bertujuan memurnikan imunoglobulin G (IgG) spesifik ASF dari dua sampel yaitu plasma konvalesen dan serum babi sebagai bahan antigen dalam pembuatan antibodi antiidiotipe ASF. Purifikasi sampel menggunakan metode pengendapan amonium sulfat bertingkat (25% dan 50%). Uji Bradford menunjukkan peningkatan konsentrasi protein sampel setelah purifikasi. Uji indirect ELISA menunjukkan seluruh sampel tetap positif terhadap ASF setelah purifikasi. Analisis SDS-PAGE memperlihatkan pita protein yang sesuai dengan IgG, yaitu light chain (~25 kDa) dan heavy chain (~50–55 kDa), dengan visualisasi terbaik pada pemanasan 95 °C selama 5 menit. Namun, pita tambahan mengindikasikan keberadaan protein nontarget. Selain itu, pita SDS-PAGE hanya teramati pada plasma konvalesen dan tidak terdeteksi pada serum. Metode pengendapan amonium sulfat mampu mempertahankan IgG spesifik ASF, tetapi kemurniannya belum optimal.

African swine fever (ASF) is a highly fatal viral disease in swine; therefore, specific antibodies are required to support antigen development. This study aimed to purify ASF specific immunoglobulin G (IgG) from two samples, namely convalescent plasma and swine serum as antigen material for production of antiidiotype antibodies. IgG was purified using stepwise ammonium sulfate precipitation (25% and 50%). The Bradford assay showed an increase in sample protein concentration after purification. Indirect ELISA results indicated that all samples remained positive for ASF after purification. SDS-PAGE analysis revealed protein bands consistent with IgG, namely light chain (~25 kDa) and heavy chain (~50–55 kDa), with the clearest visualization observed after heating at 95 °C for 5 minutes. However, additional bands indicated nontarget proteins. Furthermore, SDS-PAGE bands were only observed in convalescent plasma and were undetected in serum. Ammonium sulfate precipitation method was able to preserve ASF specific IgG; however, the purity was not optimal.