Method for detecting the presence of biologically active agents utilizing .sup.13 C-labeled substrates

A method for detecting the presence of biologically active agents comprising the steps of:

• (a) providing a sterile, sealable container partially fillied with a previously sterilized culture medium to which has been added a sample of material to be tested for the presence of biological activity;
• said medium comprising a .sup.13 C-labeled substrate fermentable to produce singly labeled .sup.13 C.sup.16 O.sub.2 ;
• the remainder of said container being filled with a culture gas containing a known initial ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 ;
• (b) subjecting the sealed container and its contents to conditions conductive to biological activity for a predetermined period of time up to 48 hours sufficient for fermentation of the .sup.13 C-labeled substrate to produce singly labeled .sup.13 C.sup.16 O.sub.2 ;
• (c) thereafter measuring the relative proportions of .sup.13 CO.sub.2 and .sup.12 CO.sub.2 in the culture gas and determining the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in the culture gas in the container;
• and
• (d) comparing the ratio determined in (c) to the known initial ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in the culture gas to ascertain whether there has been an increase in the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 indicative of the presence of a biologically active agent.

A method for detecting the presence of biologically active agents comprising the steps of:

• (a) providing a sterile, sealable container partially filled with a sterile, non-radioactive culture medium comprising a .sup.13 C-labeled substrate fermentable to produce singly labeled .sup.13 C.sup.16 O.sub.2, the remainder of said container being filled with a culture gas;
• said container comprising means for introducing a sample of material to be tested for the presence of biologically active agents into the container;
• (b) introducing a sample of material to be tested fo biological activity into said container and sealing said container;
• (c) determining the initial ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in said culture gas;
• (d) subjecting the sealed container and its contents to conditions conductive to biological activity for a predetermined period of time up to 48 hours sufficient for fermentation of the .sup.13 C-labeled substrate to produce singly labeled .sup.13 C.sup.16 O.sub.2 ;
• (e) thereafter measuring the relative proportions of .sup.13 CO.sub.2 and .sup.12 CO.sub.2 in the culture gas and determining the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in the culture gas in the container;
• and
• (f) comparing the ratio determined in step (e) to the initial ratio determined in step (c) to ascertain whether there has been an increase in the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 indicative of the presence of a biologically active agent.

A method for detecting the presence of biologically active agents comprising the steps of:

• (a) providing a sterile, sealable container partially filled with a sterile, non-radioactive culture medium comprising a .sup.13 C-labeled substrate fermentable to produce singly labeled .sup.13 C.sup.16 O.sub.2, the remainder of said container being filled with a culture gas containing a known initial ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 ;
• said container comprising means for introducing a sample of material to be tested for the presence of biologically active agents into the container;
• (b) introducing a sample of material to be tested for biological activity into said container and sealing said container;
• (c) subjecting the sealed container and its contents to conditions conducive to biological activity for a predetermined period of time up to 48 hours sufficient for fermentation of the .sup.13 C-labeled substrate to produce singly labeled .sup.13 C.sup.16 O.sub.2 ;
• (d) thereafter withdrawing a sample of the culture gas from said container measuring the relative proportions of .sup.13 CO.sub.2 and .sup.12 CO.sub.2 in said culture gas sample and determining the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in said culture gas sample;
• and
• (e) comparing the ratio determined in step (d) to the initial ratio of singly labeled .sup.13 CO.sub.2 to .sup.12 CO.sub.2 in the culture gas to ascertain whether there has been an increase in the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 indicative of the presence of a biologically active agent.

A method for detecting the presence of biologically active agents comprising the steps of:

• (a) providing a pair of identical, sterile, sealable containers partially filled with equal amounts of a sterile, non-radioactive culture medium comprising a .sup.13 C-labeled substrate fermentable to produce singly labeled .sup.13 C.sup.16 O.sub.2, the remainder of said container being filled with a culture gas;
• (b) inoculating one of the containers by introducing a material to be tested for the presence of biological activity into that container and sealing both containers;
• (c) subjecting the sealed containers and their contents to conditions conducive to biological activity for a predetermined period of time up to 48 hours sufficient for fermentation of the .sup.13 C-labeled substrate to produce singly labeled .sup.13 C.sup.16 O.sub.2 ;
• (d) thereafter measuring the relative proportions of .sup.13 C.sup.16 O.sub.2 and .sup.12 CO.sub.2 in the culture gas and determining the ratio of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in the culture gas in each of said containers;
• and
• (e) comparing the ratios of singly labeled .sup.13 C.sup.16 O.sub.2 to .sup.12 CO.sub.2 in the inoculated and uninoculated containers to ascertain whether there is a difference in the ratios indicative of the presence of a biologically active agent in the inoculated container.