Konstruksi Primer, Isolasi, dan Amplifikasi Gen α-Glucan Synthase (AGS1) Pengkode Kandidat Senyawa Imunomodulator dari Pleurotus ostreatus (Jacq.) P. Kummer 1871 = Primer Construction, Isolation, and Amplification of α-Glucan Synthase (AGS1) Gene Encoding a Candidate Immunomodulator Compound from Pleurotus ostreatus (Jacq.) P. Kummer 1871