New Products

Developed to meet the needs of analytical chemists, biochemists, and researchers in virtually any field, Sartorious Instruments, based in McGaw Park, Ill., has introduced the world's first toploading microbalance. The M3P Toploading Micro-balance is sensitive to 1 ug (with a maximum capacity of 3 g) and has three sensitivity ranges. The compact balance saves laboratory space and, unlike conventional microbalances, eliminates the need for a large weighing chamber. Since no mechanical devices for extension and retraction of the weighing pan are necessary, the M3P stabilizes quickly (in approximately eight seconds) and can be adjusted to different laboratory stability conditions. The new microbalance requires no door opening or closing, and no lock-down procedures. Listed at $8,925, it allows for rapid sample deposit and retrieval, as well as for quick stabilization. Sartorious Instruments

Through the use of infrared technology, the Foxboro Co., based in Foxboro, Mass., has enhanced its ambient air analyzer, resulting in increased sensitivity and stability. The MIRAN lB2 Portable Ambient Air Analyzer measures low concentrations of potentially hazardous airborne gases and vapors. Typical accurate measurements of compounds include minimal detectable concentrations of .06 ppm CO₂, .02 ppm formaldehyde, .05 ppm total hydrocarbons, .2 ppm ethylene oxide, and .04 ppm nitrous oxide. The MIRAN 1B2 is precalibrated for more than 100 OSHA-cited cornpounds and has memory space for additional user-selected and calibrated gases. The portable air analyzer features audible alarms for easy operation in indoor or outdoor environments, and comes complete with an integral keypad, LCD readout, and tamper-proof calibration controls. The MIRAN 1B2 Portable Air Analyzer carries a two-year warranty and is priced according to customer-specified instrument configuration. Foxboro

The efficiency of nucleic acid transfections can be increased by fivefold to 100-fold from conventional Ca²⁺P0₄ and DEAE-dextran methods with the use of Bethesda Research Laboratories' Lipofectin^TM reagent. The company, based in Bethesda, Md., has developed a liposome-mediated transfection reagent that has successfully transfected a number of cell lines normally resistant to other methods, such as electraporation. The cationic lipid reagent complexes DNA or RNA by ionic interaction and subsequently fuses with the cell membrane, resulting in cellular transfection. Lipofectin^TM is supplied as a solution of 1 mg/ml for $145, and is sufficient for 25 DNA or RNA transfections on 60-mm tissue culture dishes, or 10 transfections on 100-mm culture dishes. The Lipofectin^TM reagent works well for both stable and transient DNA or RNA expression. Bethesda Research Laboratories

Profusion b-gal/G represents a new generation of probes that are designed for primary antibody detection. Typically, secondary antibodies are chemically coupled to a chromogenic enzyme (or chromophore). These techniques are subject to batch-to-batch variation as well as the significant loss of resultant activity through chemical inactivation. The InFerGene Company, based in Benicia, Calif., has developed a genetically engineered fusion protein that is composed of the immunoglobulin-Fc binding sites of streptococcal Protein G and the enzymatically active E. colib-galactosidase. This approach has resulted in a secondary antibody probe with high specific activity and consistent characteristics. Protein G preferentially recognizes IgG, in contrast to Protein A, which recognizes 1gM Sand IgA. The reagent, priced at $55/mi (with recommended working dilutions of 1:4000), is marketed primarily for ELISA assays utilizing an o-nitrophenyl b D-galactopyranoside (0MPG) chromagen reaction. InFerGene

Particularly suitable for use in a lammar flow hood, the new compact sterilizer from Fine Science Tools Inc., in North Vancouver, B.C., offers a convenient chamber for use by biomedical and basic researchers. The chamber, filled with tiny, heated glass beads, can be left on all day and is ready to use at any time. Instruments are cleaned in the usual manner and inserted into the chamber, where sterilization occurs at 250°C for five to 10 seconds. Priced at $485, the new sterilizer is an affordable addition to most every workstation. Fine Science Tools

Designed for use with Quick-Count QC-2000 and QC-4000 Benchtop Radioisotope Counters, the FL-2000 Flow Module from BIOSCAN, based in Washington, D.C., allows biochemists and molecular biologists to count ³²P and ¹²⁵I directly as samples elute from liquid chromatography columns. The FL-2000 obviates the need for scintillation fluids or crystals and eliminates user handling of radioactive samples. Eluant tubing is run through the flow module, and samples are counted as they elute from the column and prior to sample collection, thus providing a direct view of the elution profile. The reliability of the Flow Monitor has been demonstrated in comparison to the time-consuming, laborious task of counting individual fractions. The Quick-Count Flow Monitor is ideal for use in the separation of ³²P-labeled oligonucleotides. The tabular data provide a rapid means of selecting the fractions to be pooled, calculating the percent incorporation, and computing the activity of the final product. The FL-2000 Flow Module provides an inexpensive, compact hardware and software system, allowing for easy setup, data tabulation, peak integration, and scaled plots. The product is available as an add-on module with software and printer for $1,800: complete systems start at $3,450. BIOSCAN

The Drummond Aqua-Cap^TM has been developed as a single-use dispensing glass capillary pipet. A factory installed hydrophobic plug determines the volume and serves as a piston that, when pressed downward by a reusable plunger rod, delivers the sample. Potential cross-contamination is eliminated, since the Aqua-Cap^TM is not reusable and is disposed of after use. The disposable microdispensers are available from Drummond Scientific Co., based in Broomall, Pa., in 10- to 100-mi sizes. Packages of 100 with five plunger rods are plain or heparin-coated. Prices range from $15 to $17. Drummond Scientific