Antibody binding in altered gravity: implications for immunosorbent assay during space flight.
A single antibody-incubation step of an indirect, enzyme-linked immunosorbent assay (ELISA) was performed during microgravity, Martian gravity (0.38 G) and hypergravity (1.8 G) phases of parabolic flight, onboard the NASA KC-135 aircraft. Antibody-antigen binding occurred within 15 seconds; the level of binding did not differ between microgravity, Martian gravity and 1 G (Earth's gravity) conditions. During hypergravity and 1 G, antibody binding was directly proportional to the fluid volume (per microtiter well) used for incubation; this pattern was not observed during microgravity. These effects in microgravity may be due to "fluid spread" within the chamber (observed during microgravity with digital photography), leading to greater fluid-surface contact and subsequently antibody-antigen contact. In summary, these results demonstrate that: i) ELISA antibody-incubation and washing steps can be successfully performed by human operators during microgravity, Martian gravity and hypergravity; ii) there is no significant difference in antibody binding between microgravity, Martian gravity and 1 G conditions; and iii) a smaller fluid volume/well (and therefore less antibody) was required for a given level of binding during microgravity. These conclusions indicate that reduced gravity would not present a barrier to successful operation of immunosorbent assays during spaceflight.
Maule
Jake
J
Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, USA. Jake.Maule@jsc.nasa.gov
Fogel
Marilyn
M
Steele
Andrew
A
Wainwright
Norman
N
Pierson
Duane L
DL
McKay
David S
DS
D000937:Antigen-Antibody Reactions / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D018470:Gravity, Altered; D018471:Hypergravity; D012212:Rheology; D013026:Space Flight; D014893:Weightlessness; D001616:beta-Galactosidase / Q000276:immunology
D001616:beta-Galactosidase