More Shanghai firms have joined the nucleic acid testing program to meet surging demand, which will expand testing capacity citywide and cut waiting time for sampling and results, local officials said on Thursday.Several Shanghai-based medical and high-tech firms have applied for sampling and testing service qualifications.They are expanding capacity for nucleic acid testing, a key strategy for pandemic prevention and control in Shanghai and China, in the city's high-tech and industrial zones like Caohejing and Beauty Valley.The Shanghai Commission of Economy and Informatization will help them expand or apply for required approvals and qualifications quickly, the commission said.