Abstract: A magnetic stirrer wherein a relatively weakly magnetised disposable stirrer bar inside a closed container, for example a stirrer bar moulded wholly of non-isotropic ferrite, is moved with a stirring action from outside the container by a relatively powerful magnetic driver, preferably consisting of a pair of permanent magnets of neodymium boron driven in rotation as an assembly.

Abstract: A container or vessel useful in the preparation of bacterial extracts or similar analytical samples, constructed of resilient flexible plastics material and having a releasably engageable cap (3) incorporating a nozzle (8) through which liquid contents of the container may be expressed by squeezing the container, the cap being linked to the container by a double hinge comprising two strips (14a, 14b) of material which fold back upon themselves when the container is closed by the cap, the apices (18a, 18b) of the folded hinge strips together providing contact points upon which the capped end of the container may be rested on a horizontal surface such as a work bench.

Abstract: A test for microbial growth is carried out by culturing a microorgnism to be tested in a lliquid culture medium containing an enzymatically hydrolyzable fluorogenic substrate for a period of less than about 7 hours, measuring fluorescence of the culture medium resulting from hydrolysis of the fluorogenic substrate by growth of the microorganism, continuing culturing of the microorganism in the culture medium for an additional period, and measuring microorganism growth by a non-fluorescent method as a confirmatory test of growth determined from fluorescence. Preferably, the additional culture period is overnight and the non-fluorescent method is by visual inspection. The culture medium may be in the wall of a microtitre plate, and the culture medium can contain an antibiotic to test for sensitivity of a microorganism to the antibiotic or to test for minimum inhibitory concentration of the antibiotic.

Abstract: A method of determining the susceptibility of microorganisms to an antimicrobial substance wherein the microorganisms are cultured in the presence of the antimicrobial substance, and growth or lack of growth is assessed by detecting a fluorescent product resulting from the enzymatic hydrolysis of a fluorogenic substrate. The fluorogenic substrates include 7-N-(aminoacyl)-7-amido-4-methylcoumarin, 7-N-(alanyl)-7-amido-4-methylcoumarin, or a combination of 7-N-(alanyl)-7-amido-4-methylcoumarin and 4-methyl umbelliferyl phosphate.