Abstract: An electrophoresis apparatus comprising an arched lid 2 covering an electrophoresis tank 1, a suction opening 4 set in one end of the lid 2 and an exhaust opening 7 set in the other end of the lid 2. On the outside of the suction opening 4 is set a fan 5. The fan 5 absorbs the outside air, which flows along the inner side of the lid 2 and is exhausted from the exhaust opening 7 together with the vapor generated during electrophoresis, thereby preventing clouding and bedewing of the inner surface of the lid. Consequently, the inside of the electrophoresis tank 1 can be safely observed without opening the transparent or semi-transparent lid 2 but through it.

Abstract: A hybrid vector produced from a linearized cosmid and arms from .lambda. phage vector DNA has been developed. The hybrid vector can be used to generate fragments which are useful as vectors in a helper phage-mediated transformation system, permitting large fragments of foreign DNA to be introduced into a host on an industrial scale.