Purpose

This kit has been designed to assist compliance with the requirement for drug photo stability testing imposed by the International Conference of Harmonisation’s Q1B stability testing guidelines. Quinine Sulfate is used as an Actinometry Standard.

Description and Discussion

In 1996, the ICH (International Conference On Harmonisation) issued its Q1B guideline stating that the photostability characteristics of new drug substances and products should be evaluated to demonstrate that exposure to light does not result in unacceptable change.

The substance under test is exposed to ultra-violet light under controlled conditions, using quinine as an actinometry standard, exposed under the same conditions.

The kit contains four special cells, each with a PTFE screw cap, ensuring that samples only come into contact with inert materials. They are engraved and used as follows:

  1. Sample – Test cuvette, to be filled with sample under evaluation for exposure to radiation.
  2. Control – Test cuvette, to be filled with sample under evaluation, and then wrapped in aluminium foil to protect completely from light, and used as the control.
  3. Q Sam. – Calibration cuvette, to be filled with quininesulfate solution for exposure to radiation.
  4. Q Ref. – Reference cuvette, to be filled with quininesulfate solution, and then wrapped in aluminium foil to protect completely from light, and used as the standard.
 

Catalogue Number

 

Material  Catalogue Number 

Starna Drug Photostability Testing Kit

RM-PHOTOSTABILITY 

 

Purpose

 

These reference materials have been specially developed for the validation of DNA purity measurements when performed with the dedicated low volume (< 5 ul) and short path length (< 1 mm) instrumentation offered by several vendors for use in genomics and proteomics, when sample is often at a premium. They are also ideal for qualifying conventional instruments when they are used with ultra- low volume cells such as the Starna DMV - Bio cell.

Description and Discussion

 

Dedicated low-volume instrumentation using drop technology or other measurement techniques is usually incompatible with reference materials presented inconventional spectrophotometer cells or as solid filters. Nevertheless quality control is just as important in this field,and these specially packaged versions of established Starna reference materials are designed to meet this need. The references are supplied in vials with screw-cap closure for ease of handling, from which it is easy to transfer them to the instrument under test using a micropipette or syringe.

The DNACON reference from Starna was developed as a reliable, stable and NIST traceable reference material for the validation of this method. The reference consists of a solution of a synthetic material whose spectral characteristics closely mimic those of pure DNA, but does not suffer fromthe instability and other difficulties associated with DNAitself. Two concentrations are available in vial format, to give absorbances of approximately 1 A or 0.5 A at a nominal path length of 1mm.

 

Typical spectra

 

DNACON

Absorbance values are certified at 260 nm, 280 nm and 330 nm for spectral bandwidths of 1.0, 2.0, 3.0, 4.0 and 5.0 nm . The value at 330 nm is used as a “background” correction, as in the normal methodology. From these values a corrected 260/280 ratio is calculated and reported for each bandwidth using the formula:

Ratio =   (A260 – A330)
                    (A280 – A330)

The typical calculated ratio is 1.9

 

 

Catalogue Number

 

  Catalogue Number 

Starna Microvolume DNACON Reference, 5X concentration: 1 x 1,5ml vial

DNACON5X –SC1 

2 x 1.5 ml vials

DNACON5X –SC2

4 x 1.5 ml vials

DNACON5X -SC4

Starna Microvolume DNACON Reference, 10X concentration :1 x 1,5ml vial

DNACON10X –SC1

2 x 1.5 ml vials

DNACON10X –SC2

4 x 1.5 ml vials

DNACON10X –SC4

 

Purpose

 

This Reference Material can be used for quality control and assurance of nucleic acid purity measurements using the 260/280 nm ratio method.

 

Description and Discussion

 

The ratio of the UV absorbance values at 260 nm and 280 nm is an indication of the purity of nucleic acid preparations.Pure DNA and RNA solutions will have ratios of ≥ 1.8 and ≥2.0, respectively. One potential problem with this method is that the 280 nm measurement is taken on a steep slope in the absorbance spectrum, so that a small variation in wavelength at 280 nm will have a large effect on the measured absorbance and hence the 260/280 ratio. It is important to note that avariation of ±1 nm, i.e. within the wavelength specificationtolerance of many spectrophotometers, can give rise to asignificant difference in the 260/280 ratio.

Instrument qualification using Certified Reference Materials is an essential part of any quality control programme. Reliablereference materials using DNA solutions are difficult toproduce, are inherently unstable, and the materials themselvesare often difficult to characterize, handle, package, store and certify. The DNACON reference from Starna was developed as a reliable, stable and NIST traceable reference material for thevalidation of this method. The reference consists of a solution of a synthetic material whose spectral characteristics closely mimic those of DNA, permanently heat-sealed in a far-UVquartz cell. By replicating an actual DNA sample, DNACONgives a reliable direct indication of the quality of the overall measurement process.

 

Typical spectra

DNACON

Absorbance values are certified at 260 nm, 280 nm and 330 nm for spectral bandwidths of 1.0, 2.0, 3.0, 4.0 and 5.0 nm . The value at 330 nm is used as a “background” correction, as in the normal methodology. From these values a corrected 260/280 ratio is calculated and reported for each bandwidth using the formula:

Ratio =      (A260– A330)

_______________

(A280 – A330)

The typical calculated ratio is 1.9

 

 

 

 

 

Catalogue Number

  Catalogue Number 

Starna DNACON 260/280 Reference

RM-DNA 

 

 

 

 

Purpose

These reference materials have been specially developed for the qualification of the dedicated low volume (< 5 ul) and short path length (< 1 mm) instrumentation offered by several vendors for use when sample is often at a premium. They are also ideal for qualifying conventional instruments when they are used with ultra-low-volume cells such as the Starna DMV cell. As the use of these references involves their physical transfer by the user in to the measuring device, this material is fully REACH compliant.  

Description and Discussion

Many microvolume spectrophotometers have relatively wide spectral bandwidths, up to 8 nm in some cases. Most reference materials available for instrument wavelength qualification are chosen for their well-defined spectra, with sharp absorption bands, and are usually recommended for instruments with spectral bandwidths of 3 nm or less. This is partly because most absorption bands are asymmetric, so the apparent peak wavelength will change with bandwidth, and partly because wider bandwidth instruments may be unable to resolve some peaks at all. References with sharp absorption bands may therefore be unsuitable for the qualification of these instruments.

The use of aqueous dye solutions, however, is an established and well-recognised method for the validation of the absorbance scale and linearity of a spectrophotometer. Starna Green is a specially formulated, highly stable dye solution with three broad but well-defined peaks that can be certified for both wavelength and absorbance value in the UV and visible regions, at bandwidths up to 20nm.

Typical spectra

starna-green-100

The reference is formulated to give an approximate absorbance of 1A at each of the certified wavelengths, 258, 416 and 630 nm, at a nominal path length of 1 mm.

The references are supplied in vials with screw-cap closure for ease of handling, and from which it is easy to transfer them to the instrument under test using a micropipette or syringe. Each vial contains 1.5 ml of Starna Green solution.

 

Catalogue Number

  Catalogue Number
Starna Green Microvolume reference, 1 x 1.5 ml vial RM-SG10-SC1  
Starna Green Microvolume reference, 2 x 1.5 ml vials RM-SG10-SC2  
Starna Green Microvolume reference, 4 x 1.5 ml vials RM-SG10-SC4 

 

 

The life sciences have special requirements for instrument and method validation. In genomics and pharmaceutical chemistry,limitations in sample availability and the very high cost of some reagents have led to the need to measure very small sample volumes. The need for high sample throughput is another pressure and has led to the development of highly automated procedures. The analytical equipment developed to meet these demands may not be compatible with conventional cell- or filter-based reference materials. This is, however, one of the most heavily regulated fields in science, so reliable and traceable reference materials are a fundamental component of any quality programme, and essential for meeting guidelines such as GLP and GMP.

Starna has developed a range of reference materials tailored to the special needs of this important sector.

This is a rapidly developing field, and Starna is ideally placed to assist with the development of reference materials for use in novel applications. Please contact us with your requirements.


Starna DNACON

A reliable, stable and NIST traceable reference  for the validation of nucleic acid purity measurements by the 260/280 nm ratio method.


DNACON Microvolume References

Starna can supply DNACON specially packaged for the qualification of dedicated drop technology and other low volume instrumentation. and also ideal for qualifying conventional instruments used with ultra- low volume cells such as the Starna  DMV-Bio cell. 


Starna Green Microvolume References

General purpose qualification of microvolume measurements for both wavelength and absorbance


Drug Photostability Testing Kit

Assists compliance with the International Conference of Harmonisation's Q1B stability testing guidelines. Quinine is used as an Actinometry Standard.