Wet Tank Electroblotting System

What is the Wet Tank Electroblotting System?

A buffer-filled tank that holds gel-membrane cassettes between plate or wire electrodes with a cooling core. It gives efficient and forgiving transfer of proteins across a wide size range, especially large proteins above 100 kDa.

Overview

The wet tank system is the classic protein electroblotting format. Gel and membrane sandwiches are clamped in rigid cassettes with sponges and filter paper and submerged in a tank containing 1–4 L of transfer buffer, usually Towbin buffer with methanol. Electrodes of platinum wire or stainless-steel plate on either side give a uniform field. A frozen cooling unit or a circulating coil absorbs Joule heat, and a stir bar keeps buffer homogeneous. Transfers run at 100 V for 1–2 hours, or at 20–30 V overnight at cold temperature for large proteins. Because the sandwich is fully immersed, the format tolerates small variations in assembly and is the preferred method for quantitative blots and for proteins above 100 kDa. The drawback is larger buffer volume and longer run time.

How does it work?

Blotting moves separated molecules from a fragile gel to a durable membrane while preserving their relative positions. In electroblotting, the gel and membrane are pressed together in a sandwich between filter papers and sponges or buffer-wetted stacks, and an electric field drives charged molecules out of the gel and onto the membrane, where they bind by hydrophobic or electrostatic interaction. Wet tank systems submerge the sandwich in buffer between plate electrodes, semi-dry systems place it between flat graphite or metal plate electrodes with only buffer-soaked paper, and rapid systems use high current with special buffers. Vacuum and capillary blotting draw buffer through the gel to carry nucleic acids onto the membrane. After transfer, the membrane is blocked and probed, and signals are detected chemically or by fluorescence.

What are the key features?

• Fully immersed transfer sandwich tolerates small assembly differences and supports large proteins
• Frozen cooling core or circulating coil absorbs heat during long high-current transfers
• Stir bar keeps buffer homogeneous so the field stays uniform across the tank
• Rigid cassettes hold one or two gels per tank with color-coded sides for orientation
• Platinum or stainless-steel electrodes with shrouded leads ensure corrosion-resistant contact
• Compatible with mini and midi gel formats through interchangeable cassettes

What are the technical specifications?

A typical wet tank electroblotting system configuration offers transfer area (W x L) of approx. 10 x 7.5 cm (mini) or 15 x 15 cm (midi), gels per run of 1–2 (up to 4 in large tanks), buffer volume of 1–4 L, typical transfer conditions of 100 V, 350 mA for 1–2 h; 20–30 V overnight, maximum voltage of 200 V DC and maximum current of 1.5 A. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Wet Tank Electroblotting System is used in quantitative western blotting, large protein transfer above 100 kDa, overnight low-voltage transfer and routine immunodetection. Across the wider Blotting Systems class, laboratories also deploy it for western blotting, southern blotting and northern blotting.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61326-1, ISO 17025, Ph. Eur. 2.2.31 and USP <1053>. Certification candidates for this model are CE, ISO 9001 manufacturing and RoHS; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Good contact between gel and membrane without trapped bubbles is the main factor for transfer quality, so roll out air with a tube before closing the cassette. Pre-wet PVDF in methanol and equilibrate gels in transfer buffer. Keep buffer cold or use an ice pack and stirrer for wet transfers to limit heating. Do not exceed the current or voltage limits of the tank, and follow the orientation of electrodes carefully. Clean electrodes and cassettes regularly, and do not leave buffer in the tank. Mind methanol flammability and the chemical safety of acrylamide and probe reagents. Electrical safety follows IEC 61010-1, and transfer efficiency should be checked with reversible stains or pre-stained markers.

How do I select the right Wet Tank Electroblotting System?

Select wet tank transfer for large proteins, quantitative blots or where consistency matters more than speed. It uses more buffer and takes longer than semi-dry or rapid systems. Specify gel format, number of cassettes, cooling method, maximum current and membrane size, and confirm the power supply can deliver the current.

How does it compare with other Blotting Systems variants?

Choose the transfer format from the target and the workload. Wet tank transfer is the most forgiving for large proteins above 100 kDa and for quantitative work. Semi-dry is faster and uses less buffer, which suits routine transfers of small and medium proteins. Rapid systems finish in about 7–10 minutes and suit high sample turnover but need matching consumables. Vacuum and capillary blotting are standard for Southern and northern work with large DNA and RNA fragments. Dot or slot manifolds are used when no separation is needed. Check transfer area against your gel format, membrane compatibility with PVDF, nitrocellulose or nylon, cooling options, maximum current and whether the power supply you have can drive the system.