Phosphorothioate (PS) Panels
Phosphorothioate (PS) Panels
ModDetect™ Phosphorothioate (PS) Panels provide sensitive, sequence-independent detection of PS-modified oligonucleotides across a range of analytical assays. Designed for use in biodistribution, quantification, and localization studies, these reagents help accelerate RNA therapeutic development by enabling reliable measurement of chemically modified ASOs in cells and tissues.
The Role of PS Modifications in ASO Drug Design
Phosphorothioate (PS) linkages are among the most widely used chemical modifications in antisense oligonucleotide (ASO) therapeutics. By replacing a non-bridging oxygen with sulfur, PS modifications increase nuclease resistance, extend circulation half-life, and improve tissue distribution, which are critical properties for effective oligonucleotide drugs.
Accurate detection and quantification of PS-modified molecules is essential to evaluate delivery, uptake, and pharmacokinetics during drug development. Traditional methods often rely on sequence-specific probes or complex workflows, making them less flexible for broad applications. ModDetect PS Panels overcome these challenges by enabling universal detection of PS modifications, independent of sequence or location.
Key Applications of ModDetect™ Phosphorothioate Panels
ModDetect Anti-PS antibodies provide versatile, sequence-independent tools for analyzing PS-modified antisense oligonucleotides in preclinical studies. From precise quantification to detailed tissue biodistribution and intracellular localization, these panels generate actionable data that inform therapeutic delivery, efficacy, and optimization. The following applications highlight how ModDetect antibodies support critical decision-making throughout oligonucleotide drug development.
Explore our Poster: Detection and Quantification of PS-Modified ASO in Biological Matrices using ModDetect Panel
Highly Sensitive Quantification of PS-Modified ASOs
ModDetect™ Anti-PS antibodies enable reliable quantification of phosphorothioate-modified antisense oligonucleotides across a broad concentration range. Using clone PS04, standard curves demonstrated highly specific detection down to the low picomolar range, with no signal from non-modified controls. This level of sensitivity supports accurate PK/PD measurements in both discovery and preclinical studies.
Reliable Detection of PS-Modified ASOs in Tissue Biodistribution Studies
ModDetect™ Anti-PS antibodies provide specific and reproducible detection of phosphorothioate-modified antisense oligonucleotides in tissue models. In hepatocyte studies, multiple antibody clones (PS03, PS04, PS05) showed strong staining correlated with PS content, with no background in non-modified controls. This enables accurate mapping of ONT biodistribution to support delivery assessment and candidate selection during preclinical development.
Resolve Intracellular Localization Patterns of PS-Modified ASOs
ModDetect™ Anti-PS antibodies enable precise visualization of phosphorothioate-modified antisense oligonucleotides within cells, revealing their localization to endosomal compartments and cytoplasmic regions. Using clone PS05, punctate cytoplasmic staining consistent with endosomal accumulation was observed in ASO-treated cells. These results provide valuable insight into cellular uptake and trafficking, supporting the development of more effective RNA therapeutics.
Available ModDetect™ Panels and Clones
The ModDetect™ PS Panels are available in unconjugated and biotinylated formats. Individual clones are also available for separate purchase to support custom assays or specialized workflows.
| PS Panels | Format |
| ModDetect Phosphorothioate Panel | Unconjugated |
| ModDetect Phosphorothioate Biotin Panel | Biotin |