Summary of Operational Capabilities

The Kennedy Space Center Fixation Tube (KFT) is a system designed to contain plant or other small biological samples during flight and chemically fix and stain the tissue samples.

See line drawing of KFT.

Usage

The KFT has flown on the following payloads:

Mission	Payload (Experiment)
ISS/Increment-4	BPS/PESTO (PESTO)
STS-87	CUE (BSTIC)
STS-93	PGIM-01 (TAGES)

The KFT has been used with a variety of specimens and fixatives, such as soybean (Brassica rapa) seedlings (2% glutaraldehyde + 2.5% formaldehyde), cucumber (Cucumis sativus) seedlings seedlings (3% glutaraldehyde and 5% formaldehyde + 5% DMSO), mouse-ear cress (Arabidopsis thaliana) seedlings (5-bromo-4-chloro-3-indolyl-beta glucuronide + KfeCN) and superdwarf wheat (Triticum aestivum) seedlings (3% glutaraldehyde).

Technical Details

Although plant material may not be entirely submerged in fixative, postflight analyses have indicated that excellent fixation occurs. Several researchers have hypothesized that fixation of the non-submerged portions of the specimens is due to capillary wicking of the fixative by the specimens themselves or due to the high vapor concentration of fixative inside the sealed KFT.

This hardware provides three levels of containment for the chemical fixative during stowage and operations.

The KFT is comprised of the following elements: a polycarbonate main tube where fixative is loaded preflight, the sample tube which is used to keep the plant or other specimen in place during operations, the expansion plug, top plug, base plug, and the plunger. The KFT contains approximately 35 ml of fixative solution and provides a usable sample volume of either 25 or 41 ml depending on which of the current two configurations is employed.

KFTs have proven to provide very robust containment. To date, there have been no on-orbit leaks of chemical fixative. The KFT has been demonstrated to maintain its containment at ambient temperatures, 4 degrees C refrigeration and -26 degrees C freezing.