Bacteria lysate

Wall, D. B. Lubman, D. M. Flynn, S. J. Rapid profiling of induced proteins in bacteria using MALDI-TOF mass spectrometric detection of nonporous RP HPLC-separated whole cell lysates. Anal. Chem. 1999, 71,3894-3900. 

The determination of the endotoxin with limulus amebocyte lysate (LAL) is based on gel formation of a mixture consisting of a solution of endotoxin of Gram-negative bacteria with a solution of lysate. The extent and speed of the reaction depend on the endotoxin concentration, pLL, and temperature. The reaction requires the presence of certain cations, a proclotting enzymes system, and clottable protein, which are produced by lysate. 

Split homogenized bacteria in two 50-mL sterile centrifuge tubes and centrifuge at 12,000 g for 15 min at 4°C to separate the soluble part of bacterial lysate and inclusion body fraction. Discard the supernatants, trying not to disturb the pellet (inclusion bodies). 

Fig. 9.4 The coagulation cascade in the horseshoe crab amoebocyte lysate. In the presence of LPS, the Factor C serine protease zymogen is autocatalytically activated to an active form, Factor C , which activates the proenzyme Factor B into Factor B . This in turn activates proclotting to active clotting enzyme. Clotting enzyme then converts coagulogen into a coagulin gel clot, which traps the invading bacteria...

Large populations of rhizobacteria are usually present in file rhizosphere, mainly because of die ideal environmental conditions they encounter there due to a constant supply of nutrients provided through root exudates and lysates [58]. Many of the present strains exert a disease controlling activity simply by directly antagonizing soil-borne pathogens [59,60]. In order to investigate disease suppression conditioned by ISR, it is therefore important to spatially separate the bacteria fiom the roots. 

Pyrogenic contamination is detected using two tests. In the older method, rabbits are injected with product samples, and rectal temperature is measured. Compendial limits are established with respect to how much temperature increase is permitted before the product is judged to be free or contaminated with pyrogens. The newer method involves a relatively simple in vitro technique called the Limulus Amebocyte Lysate (LAL) test. It is based on the high senstivity of amebocytes of the horseshoe crab (Limulus) to the lipopolysaccharide component of endotoxins originating from Gramnegative bacteria. The LAL test is now the USP method of choice with endotoxin limits established for most SVIs. ... 

Fig. 16.15. Photoluminescence spectra of derivatized porous silicon microcavity sensors treated with B. subtilis (Cram-(+), left spectra) or E. coli (Cram-(—), right spectra) lysates. In the top two spectra, the dark lines correspond to measurements before treatment with the bacteria the grey spectra are those obtained after treatment. The bottom two spectra plot...

In recent years, PCR-based assays have become very important as techniques for the detection of bacteria. Crude lysates or DNA extracts obtained from single colonies, as well as mixed broth cultures, colony sweeps, or even direct extracts of feces... 

Lysates from selected strains were electrophoresed along with lysates of bacteria containing plasmids of known molecular mass (Figure 2). A graph relating the electrophoretic mobilities of... 

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