Rainin Pipette Tips 250 ul Wide Orifice 15 Racks

Rainin HR-250WS Precision Pipette Tips – 250 µL, Universal Fit, Wide Orifice, Hinged Racks

The Rainin HR-250WS is a premium 250 µL universal-fit pipette tip designed for high-accuracy fluid handling, macro-molecular processing, and dispensing of viscous or shear-sensitive biological samples. Engineered to fit standard, traditional pipette shafts from a broad spectrum of major manufacturers (such as Gilson, Eppendorf, and Bio-Rad), these tips feature a specialized wide-orifice (WS) tip configuration. The broadened aperture minimizes sample flow resistance and dramatically lowers mechanical shear forces, making them ideal for processing genomic DNA, delicate cell suspensions, and dense liquid reagents. Packaged in structural, protective hinged-cover racks, these pure polypropylene tips provide highly predictable lot-to-lot fluidics consistency.

Technical Performance and Design

• Wide Orifice (WS) Fluidics: The enlarged tip opening reduces liquid flow velocity and restriction during sample aspiration and discharge. This provides gentle mechanical handling that safeguards fragile cell membranes and long-chain nucleic acids from shearing or structural fragmentation.

• Universal-Fit Shaft Engineering: Designed with a standard flexible conical collar that interfaces cleanly with traditional non-LTS pipette shafts, establishing a robust friction-based seal without slipping or losing suction.

• Heavy-Duty Hinged Cover Racks: Supplied in robust, reusable polypropylene racks equipped with dual-functional hinged lids. The covers can easily flip back for rapid one-handed work or lift off entirely to conserve valuable space under crowded laminar flow hoods.

• Pure, Bio-Inert Polypropylene: Manufactured strictly under cleanroom conditions without the use of chemical lubricants, additives, or dyes. This guards delicate biological matrices from trace organic or plasticizer leaching that could interfere with enzymatic reaction assays.

Product Specifications

• Catalog Number / MPN: HR-250WS (HR250WS)

• Manufacturer: Mettler Toledo Rainin

• Maximum Volumetric Capacity: 250 µL

• Tip Technology: Universal Fit (Traditional Shafts)

• Specialty Format: Wide Orifice / Wide Bore (WS)

• Filter Matrix: No (Non-Filtered)

• Sterility Status: Non-Sterile (Fully Autoclavable at 121°C for 20 minutes)

• Grid Array Profile: 96 Tips per Rack

Key Benefits & Applications

• Viscous & Slurry Dispensing: The wide-bore profile excels at pipetting thick, high-viscosity laboratory reagents, including glycerol, cell lysates, organic solvents, and dense microbiological growth broths, without causing tip line clogs.

• Delicate Cell Culture Work: The optimal choice for handling sensitive mammalian primary cells, stem cell clusters, and fragile spheroids where high friction and narrow orifices would cause extensive cellular lysis.

• High-Throughput Assay Preparation: Rigid matrix racks hold tips perfectly vertical, facilitating swift multi-channel alignment and attachment for rapid 96-well block compounding or sequential enzyme plate setup.

• In-House Validated Sterilization: Arriving clean and ready, both the polypropylene tips and structural racks can be safely autoclaved repeatedly to create a customized sterile barrier tailored to internal laboratory protocols.