Immediate Data

Immediate data without sending samples to other labs for analysis

Actionable Data

Actionable data to allow for quicker process understanding and design of experiments

Reduce Time

Reduced time needed for process development

Easy transfer

Easy transfer to later stage processes in Pilot or GMP

No More Sampling

No more long, hold steps for A280, which can take up to 8 hours

Multiple Drug Modalities

Proteins, DNA, Vaccines, AAV

When directly integrated into one or more locations of a process stream, the FlowVPE System reveals process characteristics that, until now, have been hidden due to the limitations of the most commonly-used, on-line, fixed-pathlength UV-Vis solutions. 

Capable of making spectral and fixed-point measurements at wavelengths between 190 nm and 1100 nm, at pathlengths between 5 microns and 8 millimeters, the FlowVPE System is adaptable to a wide range of sample types and concentrations. It can support lab scale flow lines of 3 mm, pilot scale flow lines of 10 mm, and manufacturing scale of 22 mm.

The flexibility and robustness of the technology is unparalleled when compared to traditional UV-Vis techniques and equipment.

Stainless Steel Construction: Robust stainless head design to withstand process environment

Removable Flow Cells: System comes with two removable Flow Cells of 3 mm and a 10 mm ID (larger sizes available upon request)

Direct Measurement: Concentration measurement at the absorbance max ensures accurate quantification

Low Dead Volume: 

  • 3 mm Flow Cell volume: 0.75 mL
  • 10 mm Flow Cell volume: 10 mL 
  • 22 mm Flow cell volume: 55 mL

Rapid Acquisition: Concentration acquisition every five seconds

Education/Support: On-site installation and training included with system purchase

Linear Range Finder Technology: The system automatically identifies the linear region of section data sets to verify compliance with Beer-Lambert law

Integration Options: The system comes with a 4 mA–20 mA and 0 V–5 V analog output


  • Cary 60: 22” x 8” x 19”
  • FlowVPE Head: 7” x 8” x 16”
  • Computer (Dell Latitude Rugged Extreme Laptop, open): 13.5” x 12” x 12”


  • Cary 60: 40 lbs
  • FlowVPE Head (without Flow Cell): 17 lbs
  • Flow Cell: 1.5 lbs
  • Computer (Dell Latitude Rugged Extreme Laptop): 8 lbs

*Spectroscopic Engine: Agilent Cary 60 spectrophotometer

Process Contact Materials: 

  • EPDM and platinum cured silicone seals
  • 316L stainless steel 
  • UV grade fused silica
  • Medical grade epoxy
  • Polyimide
  • Teflon seals

Maximum Pathlength: 8.000 mm

Minimum Pathlength Step: 0.005 mm

  • **Slope Repeatability: ±2%
  • Proximity to Cary 60: Delivery Fiber optic standard length 3 m (optional 6 m cable available upon request)
  • Cary 60 Power Requirements: 100V–240 V AC, Frequency 47Hz–63 Hz
  • FlowVPE Power Requirements: FlowVPE unit contains no power supply (powered via Cary 60)

*Photometric performance characteristics are based upon the Cary 60 spectrophotometer specifications and are applicable to the Cary 60 independent of the CTech FlowVPE System.
**Repeatability performance requires properly validated method and controlled homogeneous samples.

Protein A280

The FlowVPE System’s in-line variable pathlength system can provide accurate measurement during the downstream process from 0.1 mg/mL to more than 250 mg/mL for an antibody of EC 1.5. No need to remove samples for testing or disrupt production flow. 

Learn More

Drug Antibody Ratio (DAR)

The FlowVPE System can be used to measure the DAR value of antibody drug conjugates (ADC) inline. The software allows the system to measure the ratio between the payload and the protein in real time.

Learn More

Operating System: Windows 10 Compatible 

Software Environment: Agilent Cary WinUV Software Suite Version 5.0/5.1 Through (1042)

VPT Software Control: CTech SoloVPE Software Version 3.1

Required Computer Hardware: Per the minimum requirements of the Agilent Cary WinUV Software Package:

  • Recommended: 
    • Min Processor: Intel i5
    • Min Hard drive: 250 GB (SSD preferred)
    • Min RAM: 8 GB
FlowVPE Vessel Holder

CTech Variable Pathlength Technology Consumables

The quality of our Fibrette® Optical Components, sample vessels, instruments, and our service is unmatched.

View Consumables