A multi-mode apparatus for capturing light patterns emitted or absorbed by a planar sample, such as an electropheresis gel, is made possible by a unique tray and sample holder system which positions a sample at a pre-determined focal plane of the solid state camera integral to the apparatus. Each sample is fixed in a sample holder specific to the mode of labeling of the sample. The tray is configured to retain each sample holder at a different elevation with respect to the side walls of the tray for proper placement of the sample at the focal plane. The tray side walls are adapted to position a sample holder at the proper elevation depending on the sampling mode and illumination technique selected. The sample holder includes a combination of transparent, translucent, or opaque plates designed to allow illumination and imaging of the sample for the particular labeling method employed.

An improved gel plate assembly for electrophoresis, is described. It comprises glass-like sheet supports between which is placed the gel, at least the back support being a composite comprising a thermally conductive plate in contact with the glass-like sheet; and in contact with the conductive plate, a glass-like sheet that serves as a replacement support, when the composite is reversed, if the first sheet is scratched.

An apparatus for electrophoresing a sample and for thereafter either scanning in the visible mode or the fluorescent mode, under control of a central processor, to provide scanning densitometry of the electrophoresed sample, and with the fluorescent mode scanning being performed in situ. The apparatus includes a gantry which moves from left to right in the XY plane. The gantry draws, delivers and deposits the samples and reagents, and includes safety devices to prevent the gantry from movement and damage when there are obstructions in the path of the gantry. A fluorescent scanning unit is moved by X- and Y-direction motors to position a photomultiplier over an electrophoresed sample. In this way, the electrophoretic sample can remain fixed in place during sample delivery, ultraviolet exposure and measurement operations.

A support system for an equipment housing includes a pair of screw-adjustable legs at one end of the housing and a pivoting trestle at the other end. The pivoting trestle is made of two channel members, one nested inside the other. The channel members have side walls, and a bolt extends through holes in the side walls to pivotally mount one member with respect to the other. Alternatively, the members can be pivotally connected together using a ball-and-socket or cylinder-and-sleeve connection. The housing can be levelled by adjusting the effective length of the two legs, and the trestle automatically pivots to accommodate these adjustments as they are made.

An electrophoresis apparatus for automatically performing medical assays includes an electrophoresis platform which cooperates with a gantry assembly. The electrophoresis platform and the gantry assembly are movable along paths that are perpendicular to each other. An applicator assembly includes pipettes which transfer fluid samples from a specimen tray to an electrophoresis plate mounted on the electrophoresis platform. The electrophoresis platform then moves to a position into the gantry assembly, where electrophoresis is conducted to separate the samples into different fractions. The electrophoresis platform then moves beneath a reagent pouring station where a reagent is applied to make the separated fractions fluoresce under ultraviolet light. The electrophoresis platform is then moved beneath the gantry assembly again, and an air knife in the gantry assembly spreads the reagent. After incubation and drying of the electrophoresis plate, the electrophoresis platform and gantry assembly are moved relative to one another while the electrophoresis plate is read with the aid of ultraviolet lamps and a photomultiplier tube mounted in the gantry assembly. The gain of the photomultiplier tube is automatically adjusted and the data gathered is automatically edited to remove background noise. The edited results can be printed or displayed on a video monitor. Techniques for calibrating the electrophoresis apparatus are also disclosed.