XS probes


XS Probes

Design shorter qPCR probes with increased stability and increased specificity. 


Cost-effective alternative MGB Moiety probes
Greater Stability

Proprietary Modified Dual Labelled Probes with increased hybridization stability

Shorter Probe Design

Design shorter probes - Typically 15 - 25 nts in length

Increased Specificity

Due to their shorter length XS Probes offer improved target specificity compared with standard dual labelled probes

Ideal for SNP Genotyping

Deal with challenging targets for applications such as SNP Geneotyping, Gene Expression Analysis, Pathogen Detection etc.

Fast turnaround time

Delivery within 5-7 working days

Ready to go Assays

Order your primers and XS probes premixed with our Oligo Dispensing Service

Product Overview


Greater stability - Shorter probes - Increased specificity

The XS Probe range from Biolegio are a range of proprietarily modified dual labelled probes with increased hybridization stability compared with standard dual labelled probes. This increased stability allows for shorter probe design (Typically 15-25 nts), offering increased specificity for more challenging targets for applications- such as Single Nucleotide Polymorphism (SNP) Genotyping.


XS Probe design

Provide your ideal XS probe sequence (Typically 15-25nts) and your target Tm (Melting Temperature) for clear discrimination and we'll design and synthesise your XS probe to your specification.


Broad choice of Dye / Quencher

In nearly all cases XS probes are compatibility with the same Fluorophore - Quencher combinations as their standard dual labelled probe equivalents - allowing full flexibility with your available qPCR instruments. 


Scale, yield & method

qPCR probe scale and length
Biolegio three different synthesis scales for qprobes oligos: 40 nmol, 200 nmol and 1000 nmol. Prices include synthesis of maximum 40 nucleotides.


Yield XS probes


  • 40 nmol scale:    approx. 5 nmol min. yield
  • 200 nmol scale:   approx. 20 nmol min. yield
  • 1000 nmol scale: approx. 60 nmol min. yield



Premixed assays

Order your XS probes and accompanying primers delivered premixed according to your specifications with our Oligo Dispensing Service. 



XS probes can incorporate numerous 5', 3' and internal modifications from an extensive list. 


How can I fit modifications to my XS qPCR probe?
Select the modifications of your choice in our webshop or in our excel ordering sheet. In the webshop you can have instant pricing insight. Select 'XS probe' in the orderform as the chemistry used and select the modifications from the available list as required.

How can I add mixed bases to my oligo?
Use the standard code letters for mixed bases / wobbles. 



All qPCR probes including XS Probes are delivered HPLC purified as standard, this is included in the price. 



Format & concentration

Your qPCR probe can be shipped dry or desolved or mixed. Standard probes are delivered desolved in a tube in a concentration of 100 pmol/ul. Custom concentrations are available on request. 


Available buffers


  • H20 buffer
  • Tris buffer

Your primers and probes delivered as a ready-to-use assay?
Probes can be deliverd in any format, concentration or combination. Have a look at our oligo dispensing service for more information about this topic.



All your DNA oligos are delivered with a specification sheet including GC-content, molecular weight, melting temperature (Tm), OD value, sequence and quantity in μgram and nmol. 



A stringent quality control system ensures that you can expect the quality of our oligonucleotides to be of the highest standard. Before the synthesis, all chemicals are checked to meet our quality standards. During the fully automated oligo synthesis, all steps of the synthesis are monitored by multiple control functions on our DNA synthesizers. This way we can assure the coupling efficiency of the synthesis to meet our demands.


Synthesis is followed by further quality controls to guarantee the quality of the oligos. All oligos are routinely analyzed by optical density (OD) measurement. In addition, oligos are randomly analyzed by gel electrophoresis and Liquid Chromatography Mass Spectrometry (LCMS). If an oligo does not meet our requirement it’s resynthesized. The result of our stringent QC process is a product of the highest standard. All oligos are delivered with our product specification sheet, which includes: % GC content, yield in nmol and μgram, OD, melting temperature and molecular weight (MW).


ISO quality management

ISO is an independent, non-governmental membership organisation and the worlds largest developer of voluntary international standards. Biolegio’s manufacturing facility is ISO 9001:2015 and ISO 13485:2016 certified. Achieving these certificates ensures good, reliable and safe products as a result of strong product quality and manufacturing procedures and an ongoing development of our quality management system. This ongoing development empowers us to continuously strengthen our ability to identify and exceed the needs and expectations of our customers.