Resolution was better. Six bands, which migrated between the pH 5.2 and 5.85 markers, were resolved. Because the protein was not glycosolated and had no disulfide bonds, the charge variants observed by IEF were the major forms of molecular heterogeneity requiring characterization. "

LC/MS/MS

Liquid chromatography with tandem mass spectrometry detection has the abbreviation LC/MS/MS when the detector is an atmospheric pressure ionization triple-quadropole mass spectrometer. This combination of well-known technologies has a long history. Advances are incremental.

Zhang YL, Christians U, Simultaneous quantitation of Naysol and Bakuchiol, Two multiple biological activities compounds isolated from Chinese herbal medicine by semi-automated LC-MS/MS. University of Colorado Health Sciences Center, Denver CO.

Cohen M, Zhang YL, Galinkin J, Zuk J, Christians U. Quantitative determination of ketorolac in human plasma by HPLC/MS/MS. University of Colorado Health Sciences Center, Denver, CO; and The Children's Hospital of Denver, Denver, CO;

Christianson CD, Needham SR. Development of a novel HILIC HPLC/MS/MS bioanalytical method for the quantitative analysis of carboplatin from the plasma of mouse. Alturas Analytics, Inc., Moscow ID.

Limulus Amebocyte Lysate (LAL)

NASA does not want to send endotoxins into space. NASA uses a variety of methods to measure, control and reduce spacecraft microbial contamination for planetary protection purposes.²¹ Assembly of spacecraft hardware is carefully controlled and often takes place in clean-room facilities using, aseptic techniques in order to meet planetary protection requirements. Dry heat microbial reduction techniques first used on the Viking spacecraft are still used today. Measurement techniques are cultivation-based microbial assays using well-characterized biological methods.

The Limulus Amebocyte Lysate (LAL) assay method currently under development tests for the presence of microbial cell wall materials. The method is based upon an enzyme cascade, isolated from the blood cells, or amebocytes, of the primitive horseshoe crab, Limulus polyphemus, which is part of its anti-microbial defense mechanisms. The method detects lipopolysaccharide (endotoxins) and beta glucan from Gram-negative bacteria, yeast and mold, which is a general indicator of the bioburden present on space-bound hardware.

The LAL method was originally developed for use in the pharmaceutical industry, where the presence of endotoxin in injectable drugs and medical devices is known to cause fever in patients. Its application under development for planetary protection has been adapted to the use of ultra-clean polyester swabs to sample spacecraft surfaces. Microbial material is extracted from the swab with water and quantified using either a portable instrument or laboratory-based microplate reader. The method has several strong points; it is exquisitely sensitive (10-12 g lipopolysaccharide), rapid (15-30 min), and reactive with both live organisms as well as organic material from dead or non-cultivable organisms. Research is continuing that would further increase the breadth of microbes reactive to the assay. This would further improve its usefulness to assess microbial bioburden and organic cleanliness of spacecraft.