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.Facility Manager(s)
Kennedy Space Center, Space Life Sciences Laboratory, Cape Canaveral, FL, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)ISS Expedition Duration
December 2001 - March 2010Expeditions Assigned
4,16,17,19/20,21/22Previous ISS Missions
The KFT has been utilized by investigations on ISS Increment 4 (PESTO), 16 and 17 (CWRW).Availability
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.
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, Stutte GW, Reed DW, Wells HW, Ferl RJ, Norwood KL. 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.