DHS MD-12 12-Channel Fully Automated Liquid Dispenser

Overview

The DHS MD-12 is a precision-engineered 12-channel fully automated liquid dispenser designed for high-reproducibility volumetric dispensing in routine and regulated laboratory environments. Utilizing calibrated peristaltic pump technology coupled with stepper motor-driven actuation, the MD-12 delivers consistent fluid transfer across a broad dynamic range—from low-volume microdispensing (5 µL) to high-capacity bulk transfers (up to 100 mL per channel). Its architecture adheres to fundamental principles of positive-displacement liquid handling, ensuring minimal carryover, reduced aerosol generation, and intrinsic compatibility with viscous, volatile, or protein-rich reagents. The system operates without requiring air displacement or tip-based aspiration, eliminating tip cost overhead and cross-contamination risks associated with traditional pipetting workflows. Designed for integration into ELISA, coagulation assay, cell culture seeding, and reagent pre-aliquoting workflows, the MD-12 supports both discrete and continuous dispensing modes—enabling flexible adaptation to multi-step protocols without hardware reconfiguration.

Key Features

• 12 independent dispensing channels with factory-calibrated, autoclavable dispensing manifolds—available in fine-bore and standard-bore configurations for optimal performance across viscosity ranges
• Adjustable deck height (5–85 mm) accommodating diverse consumables: 6-, 24-, 96-, and 384-well plates; PCR plates; deep-well blocks; and tube racks (with optional adapters)
• 7-inch high-resolution capacitive touchscreen interface with intuitive, menu-driven navigation—supporting English-language operation and context-sensitive guidance
• Five-step dispensing speed control (ultra-slow to rapid), programmable per channel or group, enabling optimization for shear-sensitive biomolecules or high-throughput screening
• Integrated back-suction function to recover residual liquid from tubing—minimizing reagent waste and preventing cross-sample contamination
• Onboard storage for up to 100 user-defined protocols, including preloaded templates for coagulation assays and ELISA plate preparation
• One-touch oscillation mixing mode with adjustable amplitude and duration for post-dispense homogenization within wells
• Automated cleaning cycle with configurable rinse volume, frequency, and solvent selection—compatible with aqueous and mild organic wash solutions

Sample Compatibility & Compliance

The MD-12 accommodates standard ANSI/SLAS-compliant microplates (including skirted, semi-skirted, and non-skirted formats), PCR strips, conical tubes (0.5–50 mL), and custom labware via modular adapter plates. All wetted components—including tubing, manifolds, and fluid pathways—are constructed from medical-grade silicone and chemically resistant polymers compliant with USP Class VI and ISO 10993-5 standards. While the instrument itself does not bear CE-IVD or FDA 510(k) clearance, its operational parameters and documentation structure align with GLP and GMP-aligned quality systems. Data integrity features—including timestamped protocol execution logs, user login tracking, and audit trail-ready event records—support compliance with FDA 21 CFR Part 11 when deployed within validated IT environments. Routine calibration verification can be performed using gravimetric methods traceable to NIST-certified weights, satisfying internal QC requirements under ISO/IEC 17025.

Software & Data Management

The embedded firmware supports hierarchical user access levels (Operator, Supervisor, Administrator) with password protection and session timeout. Protocol creation utilizes a visual step editor with drag-and-drop logic blocks for dispense, mix, pause, and clean actions. All executed runs generate immutable .csv log files containing date/time stamps, operator ID, selected program, actual dispensed volumes (calculated from pump rotation counts), and error codes—exportable via USB port. No proprietary software installation is required for basic operation; however, optional PC-based configuration tools enable batch protocol import/export, remote monitoring via Ethernet, and integration with LIMS through RESTful API endpoints (available under extended support agreement). Audit trails retain full history of parameter changes, user logins, and calibration events for minimum 12 months.

Applications

• High-fidelity reagent pre-aliquoting for ELISA, lateral flow assay development, and molecular diagnostics kit assembly
• Uniform cell suspension dispensing into multiwell plates for proliferation, cytotoxicity, and transfection assays
• Coagulation factor dilution series preparation with sub-microliter accuracy in PT/aPTT testing workflows
• Buffer and media dispensing for bioprocess intermediate sampling and QC testing
• Serial dilution setup for qPCR master mix preparation and standard curve generation
• Automated filling of diagnostic cartridges, microfluidic chips, and sample collection devices

FAQ

What types of liquids can the MD-12 dispense reliably?
The MD-12 is optimized for aqueous buffers, saline solutions, serum-containing media, and low-viscosity organic solvents (e.g., ethanol ≤70% v/v). Viscosities up to 20 cP are supported with fine-bore manifolds; higher viscosities require validation with standard-bore configuration.
Is the system compatible with third-party plates and tubes?
Yes—provided they conform to ANSI/SLAS dimensional standards. Non-standard labware requires mechanical adapters, which are available as optional accessories.
How often does the system require recalibration?
Factory calibration remains stable for ≥12 months under normal use. Gravimetric verification is recommended before critical assays or after manifold replacement.
Can dispensing parameters be locked to prevent unauthorized modification?
Yes—Supervisor-level users may restrict editing rights on specific protocols, and Administrator-level settings enforce password-protected parameter lockout.
Does the MD-12 support barcode-triggered dispensing?
Not natively; however, external barcode scanners can be integrated via TTL/RS-232 input to initiate predefined programs through optional I/O expansion modules.