you can easily isolate the ascus and put it on the paper of upper plate of the petridish. in upper plate u can put sterlized paper and lower plate u can put pda media. keep it in inverted position. automatically the ascus brust and the ascospores release. and observe the ascospores on the zoom micros cope and mark them in inverted position position of the plate then take the disc to inoculate in the other plate.