Abstract: Wedge spacers for forming slab gels of increasing cross section are manufactured from strips of thermoplastic material by impressing corrugations into the strips which run lengthwise from one end of each strip to a point along the strip between the two ends. The corrugations decrease in depth from a maximum at the strip end down to flatness at their terminus on the strip face. The forming technique imparts a high degree of reproducibility to the spacers, while still insuring a tight seal.

Abstract: An integrated plate structure provides a novel component for use in an electrophoretic sequencing cell. The integrated plate structure consists of a glass plate and a plastic plate bonded together along a raised edge of the latter, the edge extending along the sides and bottom of the plastic plate. The plates thus form a permanent enclosure for an upper buffer solution, open at the top for filling. The glass plate further serves as one of the two glass plates forming the gel enclosure.

Abstract: A closure for containers which is inexpensively and easily manufactured and is readily removeable in whole or in part to gain access to contents in the container. The closure comprises a generally flat cap member sealed at its periphery to the mouth of the container. An upstanding tubular member on the surface of the cap is partially surrounded by a score line in the cap and the score line preferably continues all around the cap near its periphery. The tubular member preferably has rigidifying means in its closed top and side walls which can be readily flexed inwardly so that the tubular member can be firmly grasped and pulled to readily initiate a rupture in the score line at a stress-concentrating focal point on that portion of the score line adjacent the tubular member. The cap can then be easily removed by continued pulling of the tubular member.

Abstract: The device comprises a closed container with a breathing tube and a means for variably adjusting the size of an aperture into the container. A transparent inclined tube is mounted on the container and houses a moveable air flow indicating member. The tube has a passage at the top leading into the container and a vent at the bottom of the tube allows air to enter to move the flow indicating member up the inclined tube. Air drawn from the container by inspiring through the breathing tube is replaced in part by air entering through the variable aperture means and by the air entering through the vent. By adjusting the size of the variable aperture, one can determine inspiratory capacity as correlated with the amount of air necessary to move the flow indicating member to the top of the tube or to an intermediate position in the tube.

Abstract: The device is a disposable compact unit comprising a transparent column with an aperture at its base, an air float within the column and with the column mounted on a closed container. A conduit joins the top of the column to an opening into the container. The container is also equipped with a breathing tube and a variable aperture means for varying the size of another opening into the container. By inhaling through the breathing tube, a patient can judge his capacity for alveolar expansion by the height to which the air float rises. Adjustment to any patient's capacity can be easily made by changing the opening in the variable aperture means.