(VCS-77CSP, VCS-77CSP8) Perfusion Fast-Step System

The VCS-77 is a unique system that enables a user to rapidly select between several perfusion reservoirs, saving time and effort. These systems are comprised of a Perfusion Fast Stepper and a Mini Valve Control System.

How it works

The SF-77C Perfusion Fast Step rapidly delivers solutions to a sample and the VCS-6M/ VCS-8M Valve Control System provides the ability to change the solution flowing out of any one of the stepper outflow tubes. Combining these two systems together into the VCS-77 Perfusion Fast-Step System enables the user to rapidly select between several perfusion reservoirs, saving time and effort.

The SF-77C is designed around the 'sewer pipe' concept which requires that all solutions flow simultaneously and at the same relative velocity out of all the tubes within the stepper mechanism. The matched-velocity flow prevents mixing between adjacent outflows despite all of the solutions being simultaneously introduced into the bath. This approach permits the sample to see a 'pure' solution emitting specifically from the desired outflow tube.

Stepper solution flows

It's important to note that in addition to managing solution flow out of the SF-77C perfusion tubes, the flow within the larger chamber bath also needs to be managed since the flow velocities need to be the same.

A properly configured system will have a standard valve control system (such as the VCS-8P) directed towards controlling the main bath flow, and a separate, smaller valve control system (such as the VCS-6M) directed towards managing solution flow within the SF-77C perfusion tubes.

Using separate valve control systems for these two paths is critical for proper operation since the relative volumes and flow rates between the two are dramatically different, and one controller cannot service both demands simultaneously.

Fortunately, most users already have a general solution delivery system in place directed towards servicing the larger chamber bath, and the VCS-77C package provides the needed mini valve control system for the SF-77C.

System components

The rapid response and nominal hysteresis of the stepper allows for very short switching times and solution changes can be achieved in as little as 20-50 ms (or even as fast as ~1 ms when using a two-barrel Theta tubing). Once changed, the new solution with its specific concentration of salts or pharmacological reagents will remain stable until changed.

VCS-6M or VCS-8M

The VCS-6M or VCS-8M valve control system lies at the heart of a multi-valve perfusion system designed to automate and control the delivery of small quantities of fluids to the SF-77C.

The controller can independently regulate the function of up to six valves. Individual valves can be controlled via a manual switch or an external digital (TTL) signal. Valve transitions (opened or closed) occur at full power to insure rapid response times and are then held in place at less than half power to prevent heat transfer to solutions. An event-marker pulse, generated each time a valve is switched on, is provided at the rear of the controller for recording into your acquisition system.

VCS Software can be downloaded here.

Systems

VCS-77CSP - with 6 channel valve control system

VCS-77CSP8 - with 8 channel valve control system

System includes

• SF-77C - Perfusion Fast Step
• VC-8M - Complete 8 channel mini-valve perfusion system
• MM-33R - Right handed Micromanipulator
• MBB - Magnetic Base