Monthly Archives: November 2016

  1. Mixing in Small HPLC Vials

    V&P Scientific makes miniature magnetic stir discs which are encapsulated in PVDF or PEEK. These magnetic discs are well suited for stirring inside small HPLC vials.

    Thomson SINGLE StEP™ and eXtractor 3D™ filter Vials are designed to speed up sample prep and analysis. The plunger filter with different membranes nestles into the vial while simultaneously filtering and readying the sample for any autosampler. This is a process that minimizes any loss of sample eliminating multiple transfers. Thomson filter vials are compatible with most standard autosamplers; such as Agilent® and Waters® including the UHPLC™.

    This photo shows a Thomson eXtractor 3D™ filter vial next to a couple of V&P PVDF encapsulated magnetic stir discs.

    These stir discs have optimal liquid mixing performance with our VP 710D2 Multi Stirrus™.  This design is well suited for mixing different solutions or dissolution of powders.

    When used in conjunction with the VP 710D2 Multi Stirrus™, more than 100 HPLC vials can be mixed simultaneously.  If resolubilizing your compounds after refrigeration, or aiding in the initial solubilization of compounds is important for your procedure, then this is an easy solution for you.

     This video demonstrates stirring in both chambers, and stirring in a single chamber after the filtration step has been completed.

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  2. Stop Losing Precious Reagents to Dead-Volume!

    The VP 534-ALL is a low profile 384 reagent reservoir made with hydrophilic coated aluminum. The hydrophilic coating significantly reduces the dead-volume lost because of surface tension effects of the reservoir. The reservoir is designed to be washed and reused, and can be autoclaved for sterility.

    V-Groove Low Dead-Volume Reservoir:
    This reagent reservoir conforms to SBS standard dimensions: 127.7 mm long / 85.5 mm wide / 13.5 mm deep cavity / 15 mm tall.

    The standard microplate dimensions enable the reservoir to be used with robotic plate handlers or stackers. The specially designed hydrophilic coated grooves in the reservoir bottom reduce reagent waste, and allow consistent aspiration of minimal amounts of reagent. Dead volumes below 3 ml are possible depending on the solution, and aliquot volume.
         The hydrophilic surface allows liquids to spread out evenly, requiring only a minimal amount of starting reagent to cover the bottom. Starting volumes as low as 4.5 ml will spread, and allow 384 channel based aspiration.

    This is a photo of the reservoir with 5 ml of RPMI 1640 tissue culture medium:

    These are photos that compare 5ml media in various reservoirs.
    VP 534-ALL {lower left} shows superior distribution:
    The photo below shows 5ul droplets dispensed from a liquid handling robot equipped with a 384 channel pipet head; the droplets were dispensed onto a microplate lid. The robot aspirated 1.96ml media from the VP 534-ALL reservoir which had been filled with only 4.5ml of starting material. The droplets were consistent in size and the overall weight of the plate before and after dispensing indicated that ~5.1ul was delivered to each spot:
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