Multiple primer, kit and screening method for screening yeast strain expressed by low-protease A gene

The invention provides a multiple primer, a kit and a screening method for screening yeast strains expressed by a low-protease A gene, and belongs to the field of food detection. The problems of longtime, tedious detection process and long detection period of traditional screening of the yeast strains expressed by the low-protease A gene through detecting the vitality of the protease A are solved. The method comprises the following steps: designing the multiple primer, sequentially carrying out cDNA template reverse transcription synthesis, a multiplex PCR amplification and capillary electrophoresis separation with total RNA of the yeast strain as a template, and analyzing the obtained capillary electrophoresis separation result by using a GeXP system; and calculating the expression levelof the protease A gene based on the peak area of a peak corresponding to the key gene with an interference gene as a control, and determining the yeast strain as a low-yield protease A strain, a medium-yield protease A strain