A strain of Neisserie gonorrhoeae ATCC 31953 is described which has characteristically poor growth on chocolate agar at a temperature range of about 30°C to about 37°C In a CO 2 stmosphere suitable for growth of N. gonorrhoeae. This strain is resistant to nalidixic acid at the 5-10 mog/ml level and resistant to streptomycin at the 1000 meg/ml level or greater. The strain is suitable for a method for the laboratory diagnosis of gonorrhea, comprising the steps of (1) preparing a test strain of the microorganism Neisseria gonorrhoeae which is competent for transformation, (2) extracting N. gonorrhoeae DNA from a patient's apecimen material or colonies suspected of being N. gonor- rhoeae whether in pure or mixed culture by treatment with a base which lyses N. gonorrhoeae, (3) adusting the pH of the extract of step (2) to a pH that is not toxic to the test strain, (4) applying the pH adjusted extract to the test strain before or after putting it on or into a biological medium suitable for growth of N. gonorrhoese, (5) maintaining the treated test strain at optimum N. gonorrhoeae growth conditions which are Inhibitory for the test strain and (6) observing for detectable growth of the treated test strain. The observance of growth Indicates detection of N. gonorrhoeae DNA. Also described is a test kit for performing the method.