2002/02/06 by M.J. Harris, Nalin C. Wickramasinghe, David Lloyd +7 · 2 citations
Medicine · #Spaceflight effects on biology #Microorganism #Environmental science #Remote sensing #Biology #Geology #Bacteria
paper · doi:10.1117/12.454758
openalex publication_date 2002/02/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Air samples collected aseptically over tropical India at various stratospheric altitudes ranging from 20 to 41 km using cryosampler assemblies carried on balloons flown from Hyderabad have shown evidence of living microbial cells. Unambiguous evidence of living cells came from examining micropore filters on which the samples were recovered with the use of voltage sensitive lipophilic dyes that could detect the presents of active cells. Clumps of viable cells were found at all altitudes using this technique, and this conclusion was found to be consistent with images obtained from electron microscopy. Since the 41 km sample was collected well above the local tropopause, a prima facie case for a space incidence of these microorganisms is established. Further work on culturing, PCR analysis and isotopic analysis is in progress.