Fluid exchange in a chamber on a microscope slide

A method of adding and removing liquid reagent to and from a sample on a flat surface, comprising:

• sealing a chamber housing to the flat surface to form a chamber over the sample and flat surface, said chamber housing having at least one fluid port, a valve in each fluid port, and a reagent well outside of the chamber in at least one of said fluid ports;
• dispensing an aliquot of reagent into said reagent well located in one of said fluid ports;
• providing a source of vacuum and a conduit that channels said source of vacuum to one of the fluid ports of the chamber housing;
• and
• transmitting said vacuum to the chamber housing through one of said fluid ports and the respective valve while retaining the vacuum in the chamber;
• ceasing to apply the vacuum and causing said aliquot of reagent to flow from said reagent well into said chamber by the vacuum in the chamber.

A method of processing a sample on a flat surface with a series of reagent incubations, comprising:

• sealing a chamber housing to the flat surface to form a capillary sized chamber over the sample and flat surface, said chamber housing having fluid ports at opposite ends thereof and a reagent well in at least one of the fluid ports outside of the chamber, there being a valve in each fluid port to control fluid communication to the chamber;
• and
• for each of the series of reagent incubations:
• dispensing an aliquot of reagent into the reagent well;
• applying a vacuum to the chamber through at least one of the fluid ports and the respective valve;
• ceasing to apply the vacuum while retaining the vacuum within the chamber and subsequently allowing reagent to be drawn from the well into the chamber through the fluid port and respective valve by the vacuum retained within the chamber;
• incubating the reagent and sample;
• and
• washing the sample and flat surface by forcing a wash liquid to flow through the chamber between opposite ports and respective valves.

A method of applying reagent to a sample in a sealed chamber comprising:

• providing a well in a fluid port adapted for fluid communication with the chamber;
• providing and retaining a supply of reagent in the well in the port;
• applying a vacuum to the chamber through the reagent in the well and the port;
• ceasing to apply the vacuum while retaining the vacuum within the chamber;
• and
• after ceasing to apply the vacuum, allowing reagent to be drawn into the chamber through the port by the vacuum retained within the chamber.

A method of applying reagent to a sample in a sealed chamber comprising:

• providing and retaining an aliquot of reagent in a well on the chamber wall in a fluid port, the well being outside of the chamber and adapted for fluid communication with the chamber through the port;
• subsequently moving the chamber and fill station relative to one another;
• at the fill station, applying a vacuum to the chamber;
• ceasing to apply the vacuum while retaining the vacuum within the chamber;
• and
• after ceasing to apply the vacuum, allowing reagent to be drawn from the well into the chamber through the port by the vacuum retained within the chamber.