Abstract: A method of assay of antioxidant activity of a sample of water, which comprises monitoring the change exerted by the sample on a luminescent reaction.

Abstract: A method of assay of antioxidant activity of a biological fluid, which comprises monitoring the change exerted by the sample on a progressing luminescent reaction.

Abstract: A recording apparatus has a holder for a plurality of reaction vessels including a support plate (11) having an array of holes (15) therein for receiving an array of reaction vessels (16), a housing (10) for receiving the holder and being sealed to prevent entry of stray light, an openable cover (24, 249) for the housing, a film back (12) for holding a photographic film adjacent the underside of the plate (11), and a removable shutter (13) for interposition between the film and the support plate.

Abstract: Assays, e.g. immunoassays, based on the chemiluminescent reaction between a peroxidase enzyme, e.g. horse radish peroxidase, a chemiluminescent 2,3-dihydro-1,4-phthalazinedione, e.g. luminol or isoluminol and an oxidant, e.g. hydrogen peroxide or a perborate, are improved by carrying out the reaction in the presence of a 6-hydroxybenzothiazole, especially 6-hydroxybenzothiazole itself or firefly luciferin. Light emission from the reaction is significantly enhanced by the 6-hydroxybenzothiazole.

Abstract: It has been a problem that the chemiluminescent emission produced by the peroxidase-catalyzed oxidation of a 2,3-dihydro-1,4-phthalazinedione is often weak or gives a poor signal-background ratio and therefore does not give the high degree of sensitivity required for assay purposes, particularly for assay of peroxidase used to label a reagent for example in ELISA. The present invention solves the problem by the finding the certain narrowly defined aromatic amines are enhancers of the reaction and accordingly provides for their use in an assay and kit. The amines are of general formula (I) ##STR1## wherein the R symbols (that is, R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6) have any of the meanings (a) to (j) given below, all other R symbols in each meaning are hydrogen atoms and the fused rings are to be read in the same configurational sense as formula I:(a) R=R.sup.1 =CH.sub.3 ; R.sup.4 = ##STR2## (b) R.sup.4 = ##STR3## cyclohexyl, or alkyl or alkoxy having 1 to 4 carbon atoms (c) R.sup.2, R.

Abstract: A phenolic compound is used to enhance the sensitivity of a luminescent reaction such as carried out in an immunoassay between a peroxidase enzyme, an oxidant, and a chemiluminescent 2,3-dihydro-1,4-phthalazinedione. Preferably, the phenolic compound is 4-iodophenol, 4-phenylphenol or 2-chloro-4-phenylphenol. In the preferred embodiment, horseradish peroxidase is coupled to an antibody to the substance to be assayed.

Abstract: A dispensing device, for dispensing reagent into an array of reaction wells (16) in a photographic recording apparatus, comprises an array of tubes (28) which are mounted in a support (23). The support (23) contains a common chamber (29) into which the tops of all the tubes (28) open. The chamber (29) is connected with atmosphere via an opening (32) which is sealable manually to retain liquid in the tubes (28) when the latter are immersed in a reservoir (40) and which is unsealed to dispense the liquid. The recording apparatus has a housing (10) closable at the top by part of the support (23). A plate (11) having an array of holes (15) therethrough rests on a shutter (13) disposed above a photographic film holder (12). The plate (11) carries the reaction wells (16) in the holes (15).

Abstract: The apparatus comprises a movable member (10) which carries a plurality of cuvettes (11) containing material under test. Control means cause the member (10) to be moved to bring the cuvettes (11) successively into register with a photomultiplier (16), and in that position reagent is automatically added to a cuvette, giving rise to a luminescent reaction. Light from the reaction is detected by the photo-multiplier (16) and the resultant signal processed and recorded. The control means is triggered to stop the member (10), add reagent, record the signal from the luminescent reaction, and restart the member, from a photocell (28) which is illuminated through the member (10) only when a cuvette (11) is in register with the photomultiplier (16).According to the method, sample material containing the analyte for determination is mixed with a known amount or concentration of the same analyte labelled with a substance which is capable of taking part in a luminescent reaction.

Abstract: Apparatus for testing at least one liquid sample, by immersion therein of a probe for coaction between said probe and sample, having a reloadable sample carrier for at least one sample container; a reloadable probe carrier for at least one probe; a frame having locating means for relatively locating the sample carrier and the probe carrier laterally in the frame, parallel motion means for guiding the probe longitudinally into the sample container and stop means for locating the probe at a predetermined distance into the sample container, locking means preventing the probe from being withdrawn more than a predetermined distance in the outward direction from the sample container, timing and control means for releasing said locking means after a predetermined time, and self acting withdrawal means for withdrawing the probe and probe carrier to a position clear of the sample container; the said sample carrier and probe carrier being arranged so as to be severally removable away from the said frame.

Abstract: In testing for cleanliness a cuvette having translucent wall portions, the cuvette is preferably partially filled with pure water and then a beam of optical radiation is directed at a said wall portion, the intensity of radiation which has passed through the cuvette by direct transmission or by scattering is detected, and the state of cleanliness of the cuvette is determined from a comparison between the detected optical intensity and a criterion indicative of cuvette cleanliness.The invention finds particular application to testing cuvettes for cleanliness which have been washed in a laundry of an automatic blood analysing machine.