In an environment where sample origin and test results require correlation, the number of tests per sample is predetermined, yet variable, the samples can step along one path and the test products (aliquots) step along another path with a step ratio dependent upon the number of tests per sample, the sample carrier is subdivided into indicia bearing receivers (one for each sample), and there is established a step count-distance relationship on the one hand between the original position (transfer station) of the sample, the number of tests per sample and a fixed indicator position, and on the other hand between the original position (receiving station) of the aliquot and the testing station; whereby a presettable counter is preset to correspond to the indicia of the sample receiver in the fixed indicator position at the time of start-up and then will automatically progressively step to attain the indicia value for each sample as its aliquots are being tested and ready for test data printout; the counter feeding the printer the sample indicia at the same time that the printer is printing the test data for that sample.

In an automatic chemical testing apparatus, a reaction loop conveyor carries rows of reaction containers in a path including an upper, forward path in a direction normal to the rows. Samples for analysis are provided to the reaction conveyor from a sample source. An improved system is provided in which sample source means synchronized with the reaction conveyor index successive sample containers to an aspiration station adjacent to one row in the forward path of the reaction conveyor. The sample source means may be a sample conveyor consisting of sample container holders linked together.

In an automatic chemical testing apparatus including a reaction conveyor carrying rows of reaction containers from a sample dispensing station through a reaction station and to an analysis station, the improvement is provided in which slats containing the reaction containers are linked together to form a reaction loop conveyor without the need for a separate chain. The loop path includes first and second apexes and a forward path between the apexes. Guideways are provided to maintain the reaction container slats in an upright disposition between the forward path and the apexes. Further, a conveyor housing assembly is provided housing incubation means, reaction container washing means and means for driving the conveyor directly.

In an automatic chemical testing apparatus, means are provided for dispensing aliquots of a sample to reaction containers. A carriage means housing a self-priming hydraulic circuit mounted for motion on a support arm housing drive means. During an operating cycle, control means operate the drive means to position a conduit communicating with the hydraulic circuit over a sample source and aspirate an amount of the serum into the hydraulic circuit. The carriage means is then moved, preferably at uniform rate over a row and dispensing means are pulsed to dispense samples into individual reaction containers while the carriage means is moving. The carriage means is then returned to its starting position.

A plurality of analyzer units for serum, a plurality of analyzer units for blood plasma, and a plurality of analyzer units for urine are arranged along a main transfer line for transferring a sample rack from a rack providing portion to a rack storage portion. A reagent bottle for inspecting liver function is contained in each reagent delivery mechanism of two analyzer units among the plurality of analyzer units for serum. When the reagent for inspecting liver function in one of the two analyzer units is to be short, analysis for the liver function analysis item in the samples can be continued by transferring a sample rack from the rack providing portion to the other analyzer unit.