Collecting and recovery small assay samples of viable microbiological contaminants in a gas stream involves use of a commercially available water-soluble paper. This paper is nontoxic to a number of microbiological organisms and can be dry-heat-sterilized

Godwin, W. W.

English

NASA Technical Reports Server

August 1969	 Brief 69-10273 
.	
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information; Springfield, Virginia 22151. 
Technique for Highly Efficient Recovery of Microbiological Contaminants 
The problem: 
To devise an efficient technique for collecting and 
recovering small assay samples of viable microbiologi-
cal contaminants (I to 5 micron nominal diameter). 
The highest possible recovery efficiency was required 
because the concentration of particles entrained in 
the air or gas medium to be sampled was less than 50 
particles/ ft 2 /min. Conventional microbiological re-
covery methods are sufficiently accurate for large 
samples because statistical control procedures can be 
applied to ensure high confidence levels in estimating 
the microbiological population recovered in the sam-
ples. 
The solution: 
Of several techniques which were investigated, the 
simplest and most reliable uses a patented, commer-
cially available water-soluble "paper" as a target for 
the collection of microbiological contaminants en-
trained in a gas stream. This paper is nontoxic to a 
number of microbiological organisms and can be dry-
heat-sterilized at 130°C for 5 hours without damage. 
The organisms collected on the paper are recovered 
for. conventional microbiological assay by dissolving
the paper in sterile distilled water. Tests have shown 
that essentially 100 percent recovery of microbiological 
contaminants (e.g., as few as I spore of Bacillus sub-
ti/us var. niger) is possible with this technique. 
Notes: 
I. This technique should be useful for monitoring and 
control of small concentrations of particulate con-
taminants including various types of viable micro-
organisms. 
2. No further documentation is available. Inquiries 
may be directed to: 
Technology Utilization Officer 
Manned Spacecraft Center 
Houston, Texas 77058 
Reference: B69-10273 
Patent status: 
No patent action is contemplated by NASA. 
Source: W. W. Godwin of 
Martin Marietta Corporation 
under contract to 
Manned Spacecraft Center 
(MSC-13250) 
Category 04 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
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Technique for highly efficient recovery of microbiological contaminants

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