Abstract: The present invention is directed to provide new PCR measuring method and device. As one embodiment of the present invention, a DNA detection method for detecting DNA in a droplet being present in oil, the droplet containing the DNA and a fluorescent labeled probe, the fluorescent labeled probe being hybridized to the DNA, the method including: a first step of amplifying the DNA in the droplet by a nucleic acid amplification reaction; and a second step of measuring a melting temperature of the fluorescent labeled probe and the DNA in the droplet is provided.

Abstract: A machining oil composition comprises at least two ingredients, that is a lubricating base oil and a salt selected from sulfonates of alkali metals and the like. The composition may further comprise a metal composition selected from thiophosphates and the like, and/or sulfur-based extreme pressure agents. Since no chlorine-based extreme pressure agent is contained, little problem on the environmental pollution or the damage of incinerators is involved. The composition exhibits good machining or cutting performance.