Apparatus for dispensing a preset monetary amount of product, such as fuel, sold by volume and for use with a dispenser which calculates and displays a continuously increasing cost of the delivery has a number of selector buttons which relate to units of cost and which when selected set an appropriate number into a counter. The counter is coupled to the display, and the count is decremented by one for each unit cost of product actually delivered. During delivery of the first unit a store calcula...

Techniques for the delivery of metered amounts of liquid material include the use of a pin, such as an optical fiber. A sample of the liquid material may be placed on the tip of the pin for delivery to a target area, such as a specific location on a microarray, in a contactless manner. Light transmitted through the pin may be detected to facilitate accurate measuring of the pin's position.

A system for isolating mRNAs as cDNAs employs a polymerase amplification method using at least two oligodeoxynucleotide primers. In one approach, the first primer contains sequence capable of hybridizing to a site immediately upstream of the first A ribonucleotide of the mRNA's polyA tail and the second primer contains arbitrary sequence. In another approach, the first primer contains sequence capable of hybridizing to a site including the mRNA's polyA signal sequence and the second primer conta...

The invention relates to quantitative dosing of small amounts of liquids having a volume of microliter or nanoliter order. Such a dosing technique is useful for instance for productive serial dosing in applications of clinical chemistry. In dosing device of the invention, flexible bellows (5) attached to a body (1) define a liquid space (15) filled with a liquid to be dosed and communicate with a dosing tip (19). The bellows (5) are provided with an actuator (7) for operation thereof, constricti...

Methods of reducing background during amplification of small amounts of nucleic acids employ careful analysis of sources of low level contamination. Ultraviolet light can be used to reduce nucleic acid contaminants in reagents and equipment. "Primer-dimer" background can be reduced by judicious design of primers. We have shown clean signal-to-noise with as little as starting material as one single human cell (.about.6 picogram), E. coli cell (.about.5 femtogram) or Prochlorococcus cell (.about.3...

The invention relates to methods and apparatuses for manipulating small amounts of solids. Specific embodiments of the invention are particularly suited for the automated transfer of small amounts of solids. In one embodiment, a uniform powder bed is lightly compressed into plugs of powder and dispensed. In another embodiment, the solid is placed in a liquid carrier to form a slurry, dispensed, and the liquid component is subsequently removed. In yet another embodiment, solids are manipulated us...

A method for classifying an image as one of color and neutral assigns respective values associated with a plurality of pixels in the image to a plurality of respective current pixels. Reduced image pixels are produced as a function of the current pixels. The image is classified as one of neutral and color as a function of the reduced image pixels.

A method is used for correcting amounts of light of light emitting elements. A first correction range is defined which has a median of maximum and minimum values of the amounts of light of the light emitting elements, and includes a predetermined number of first subdivided ranges. If the minimum amount of light is not within the first correction range, a second correction reference is produced which is smaller than the first correction reference by a predetermined fraction of the difference betw...

The nitrogen content of a substance is determined by digesting the substa in a sealed container at superatmospheric pressure in a liquid acid medium until the nitrogen is converted to ammonium ions, the medium is alkalinized, and the ammonia liberated thereby is driven from the alkalinized medium into an acidic aqueous medium by steam distillation in a closed system in which the steam used is generated from the acidic aqueous medium. The latter then is adjusted to a weakly alkaline pH, and the a...

An improved technique for determining the presence of hemoglobin, having increased sensitivity, is provided by bringing the material to be tested into contact with an acidic solution of tetramethylbenzidine and hydrogen peroxide to form a mixture, allowing said mixture to stand for a predetermined period of time, and thereafter examining the mixture for the presence of a colored complex indicative of the presence of hemoglobin. Organic acid is present in a concentration generally of at least 30 ...