Kennedy Space Center Fixation Tube (KFT) - 07.29.14

Summary | Overview | Operations | Results | Publications | Imagery
ISS Science for Everyone

Science Objectives for Everyone
The Kennedy Space Center Fixation Tube (KFT) is an apparatus designed to contain plant or other small biological samples during flight and chemically fix and stain the tissue samples while providing three safety-levels of containment.

Science Results for Everyone

The Kennedy Space Center Fixation Tube (KFT), which carries and chemically fixes biological samples in space, holds promise for future molecular biological experiments. It uses a triple-redundant sealed environment for chemical fixatives extremely hazardous to humans. In a plant investigation using RNALaterTM sample preservative, the KFT resulted in better preservation. Onboard modifications also enhanced KFT’s functionality and storage potential in support of a plant gene-expression investigation. The KFT quickly preserves samples, holds potential for long-term storage without compromising RNA integrity, and offers simplified stow and descent procedures. KFTs filled with RNALaterTM can be deployed months or possibly years prior to use.



This content was provided by David R. Cox, and is maintained in a database by the ISS Program Science Office.

Facility Details

OpNom:

Facility Manager(s)

  • David R. Cox, Kennedy Space Center, Kennedy Space Center, FL, United States

  • Facility Representative(s)
  • Charles D. Quincy, Kennedy Space Center, Kennedy Space Center, FL, United States

  • Developer(s)

    Kennedy Space Center, Space Life Sciences Laboratory, Cape Canaveral, FL, United States

    Sponsoring Space Agency
    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization
    Human Exploration and Operations Mission Directorate (HEOMD)

    ISS Expedition Duration
    December 2001 - March 2010

    Expeditions Assigned
    4,16,17,19/20,21/22

    Previous ISS Missions
    The KFT has been utilized by investigations on ISS Increment 4 (PESTO), 16 and 17 (CWRW).

    Availability

  • Available for Launch
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    Facility Description

    Facility Overview

    • The Kennedy Space Center Fixation Tube (KFT) is a device for chemical fixation of a biological sample in microgravity.


    • It is small and easy to use, and is well suited to use in the field as well as in the laboratory.


    • Because typical chemical fixatives are extremely hazardous to humans, the device is also designed to contain its fixative solution within a triply-redundantly sealed environment.
    The Kennedy Space Center Fixation Tube (KFT) is a system designed to contain small biological samples during flight and chemically fix and stain the tissue samples.

    The KFT 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. The KFT has been demonstrated to maintain its containment at ambient temperatures, +4 degrees C refrigeration, and -99 degrees C freezing.

    The KFT has been shown to be compatible with many fixative reagents. Some of the tested reagents are listed below:
    • 100 percent RNAlater

    • 0.4 percent Formaldehyde (0.4 percent)

    • 5 percent formalin, 5 percent acetic acid, 50 percent ethanol

    • 0.5 percent Glutaraldehyde, 2 percent Paraformaldehyde
    In flight, in order to perform fixation of the samples, the KFT system is removed from the zip lock storage bag in which the hardware is stowed. The crew inspects the bag prior to opening to ensure there have been no leaks. After a specimen has been placed into the sample tube, a plunger is removed from the locker and inserted into the main tube to provide three levels of containment between the sample tube and the outside environment. The plunger is locked into place at the top of the tube and can not be removed from the main tube once it is engaged. The fully assembled KFT is actuated by turning the plunger handle several turns to release the internal expansion plug. Fixative is forced through openings located in the bottom of the sample tube. The expansion plug continues to be forced down until it reaches the base plug of the main tube. The specimen is now partially to fully submerged in the fixative solution thus completing the operation. The fired KFT is then replaced in the plastic bag and restowed in a locker or transferred to MELFI or other conditioned stowage as required.

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    Operations

    Facility Operations

    • The KFT includes a main tube, sample tube, expansion plug, base plug, and top-plug/plunger assembly.


    • Prior to use, the fixative solution is contained at the bottom of the main tube, below the expansion plug. The sample is placed in the sample tube, which is then inserted in the main tube and sealed in the main tube by inserting the top plug.


    • Next, the plunger is used to actuate a mechanism that loosens the seals on the expansion plug, then push the sample tube down against the sample plug, thereby pushing the sample into the fixative solution.

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    Results/More Information

    When conducting biological studies, it is important to maintain the integrity of the samples. The standard method to preserve samples is quick freezing at low temperatures, -80º C (-112º F) and below, but strict temperature control of samples on station is not always uniform or possible. Therefore, a preservation method is needed that will maintain the integrity of biological samples. In conjunction with the KFT, RNALaterTM was used to preserve some of the PESTO samples on station during increment 4. Results indicated that the method utilized resulted in a sample which was better preserved for future analysis (Paul 2005).

    Certain modifications of the KFTs were designed to enhance on orbit functionality and storage potential in support of the TAGES (Transgenic Arabidopsis Gene Expression System) investigation. The KFT main tube was shortened allowing it to fit into certain areas and changes to the actuator mechanism and the expansion plug mechanism were made to create a more reliable system. Analysis of the returned TAGES samples was performed and determined that the RNA integrity was very good. The KFT device is extremely valuable because it quickly preserves harvested samples, it holds potential for long term storage without compromising the RNA integrity and because it does not require specific temperature regulations, destow and descent procedures have been simplified. We also established that KFTs filled with RNALaterTM can be effectively deployed to orbit months or possibly years prior to use. Utilizing KFT devices creates a large window of opportunities for future molecular biological experiments (Ferl 2011).

    Results Publications

      Paul A, Levine HG, McLamb W, Norwood KL, Reed DW, Stutte GW, Wells HW, Ferl RJ.  Plant molecular biology in the space station era: Utilization of KSC fixation tubes with RNAlater. Acta Astronautica. 2005; 56: 623-628.

      Ferl RJ, Zupanska AK, Spinale A, Reed DW, Manning-Roach S, Guerra G, Cox DR, Paul A.  The performance of KSC Fixation Tubes with RNALater for orbital experiments: A case study in ISS operations for molecular biology. Advances in Space Research. 2011; 48(1): 199-206. DOI: 10.1016/j.asr.2011.03.002.

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

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    Related Websites

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    Imagery

    image KSC Fixation Tube. Image courtesy of http://www.lssc.nasa.gov/fs/lsda/.
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