Advanced Analytical Techniques - Oligoprobe Hybridization

Oligoprobe hybridization is a technique that makes it possible to confirm the genetic identity of microorganisms isolated from mixed populations within the environment.  RNA or DNA extracted from these microbes is fixed to a charged membrane such as nitrocellulose or nylon and supplemented with enzyme-labeled probes.  Following a short incubation and reaction with specific substrates, the labeling profiles are examined to determine if target species are present.

Oligoprobe Hybridization for Bioremediation

Chlorinated solvents such as tetrachloroethene & trichloroethene are common to a number of industries and are extremely resistant to degradation in the natural environment.  These compounds are being identified increasingly in the subsurface environments near industrial and military installations and may be important groundwater contaminants.  Although few microorganisms are able to metabolize these solvents, the dehalococcoides (DHC) group is capable of breaking them down to nontoxic end products such as ethenes.  However, the ecology and distribution of dehalococcoides in the subsurface is not well understood.   Because of the strong interest in promoting the growth of DHC within contaminated soils, SMI has partnered with firms that specialize in the production and use of DHC for bioremediation applications.  SMI scientists have adapted oligoprobe hybridization for use in identifying and quantifying DHC bacteria collected from subsurface samples.

Enumeration of DHC Bacteria Using Oligoprobe Hybridization

A brief description of the oligoprobe hybridization technique developed by SMI is presented below.

STEP 1: 

A water sample is incubated overnight and colonies are grown on an agar plate.

 

STEP 4:
Acid is neutralized

 

STEP 5:
Hybridization - A tag (oligoprobe) is added and binds
to specific DNA sequences.

 

STEP 6:
Substrates are added for detection of desired
colonies (dehalococcoides, DHC)

STEP 7:

SMI is committed to using innovative technologies to solve environmental problems.  In keeping with this philosophy, SMI is actively investigating alternative uses for this technology.