MS thesis viva of four MS Biotechnology students, Nowrin Nowshaba, Md. Abdul Quayum, Md. Shoyeb and Abul Kalam Azad was held on 11th, 15th and 22nd December 2011. All four students worked in various fields of biotechnology. Work of Nowrin Nowshaba and Abul Kalam Azad were aimed to analyse immune response to diarrhoea drugs. Title of Ms Nowshaba's thesis is "In vitro regeneration of three local potato (Solanum tuberosum L.) varieties of Bangladesh", while Mr. Azad's work was entitled "Comparison of memory B-cell immune response among different age groups after oral cholera vaccination". Both the research studies were carried out under joint supervision of Professor Dr. Firdausi Qadri, of ICDDR,B, and Professor Naiyyum Choudhury, BRACU. Md. Abdul Quayum worked on "Characterization of an ethanol producing yeast isolate and optimization of ethanol fermentation" and Md. Shoyeb worked on "Screening of some Bangladeshi medicinal plants for in vitro antioxidant, antimicrobial and insecticidal activities". The work on ethanol fermentation was supervised jointly Dr. Monzur Morshed Ahmed, BCSIR and Professor Naiyyum Choudhury, BRACU. The work on medicinal plant extracts was carried out at BRAC University lab under joint supervision of Dr. Ashik Mosadek, Pharmacy Dept, BRACU and Professor Naiyyum Choudhury, BRACU. The thesis evaluation exam was chaired by Professor AA Ziauddin Ahmad. Professor Dr. Firdausi Qadri snd Dr. Monzur Morshed Ahmed acted as external examiners. Dr. Mahboob hossain and Dr. Aparna Islam were among the other members of the examination committee. Some faculty members attended the viva-voce exams.