Because the Biuret method can also be carried out at 562 nm (the absorption behavior of the Biuret reagent is almost identical in the range from 530 to 570 nm), you can measure your Biuret method on the BioPhotometer using the BCA method. Please note that you need only work with a standard for the Biuret method. The measurement of a standard curve is unnecessary.

It is 3 m long.

Please check whether the factor 1.000 is found under "Parameter" on the BioPhotometer. It is possible that the factor was accidentally reset to nil when working with the BioPhotometer. In case you continue to have difficulties with measurement, please contact our Application-Hotline: Tel. +49 180 3 66 67 89; email: support@eppendorf.com.

Yes. Double-stranded ring-shaped DNA can be measured on the BioPhotometer using the "dsDNA" method, and single-stranded ring-shaped DNA with the "ssDNA" method.

Dust in the cuvette shaft can be carefully removed with a cotton tip. If the cuvette shaft is heavily soiled, for example with dried-on buffer residues, the cotton tip should be carefully soaked in 40% methanol beforehand.

The life span of the xenon lamp is influenced by neither repeated switching on and off nor by leaving it on in standby over a period of several hours. You can therefore decide for yourself. The xenon lamp is also only active during the measurement. It then switches over into standby mode.

Yes, if you are aware of a factor for double-strand RNA. You should enter this under the RNA method before the measurement under "Parameters". If you don't have a factor, you can carry out a calibration with a familiar dsRNA quantity and then use this to measure the unknown sample.

Yes, the software is valid for the BioPhotometer plus as well as for the BioPhotometer 6131!

Please check, if all systems settings as stated in the manual in chapter 2.3 are correct.

Yes, this is possible. Therefore you can use in the area "archive" the filter function.

Click top menu bar on "new archive file"!

The BDTS will only be offered in English language.

Windows XP or Windows Vista.

Negative A₂₃₀ values are usually caused by interference components in inadequately concentrated DNA solutions. The negative value should be rectified when you use a lesser sample dilution for the next measurement. Please note that you should measure at 260 nm for a minimum absorbance of 0.1 in order to obtain exact results. This value is independent of the measuring device and is based upon the disturbing influence of impurities and particles on the measurement result, which is especially high at A < 0.1.

Conversion is possible through calibration graphs or counting. With measurements of Escherichia coli, for example, it is possible to estimate roughly that an OD 600 between 0.5 and 1.0 corresponds approximately to a cell number between 1 x 108 and 1 x 109.

Please switch the BioPhotometer off and then on again following the installation of the program. The header line will then appear.

The Bradford reagent is an aggressive substance that attacks the plastic of plastic cuvettes when the exposure time is too long. This reagent should therefore not remain in a plastic cuvette for more than 5 minutes. Fluctuating values could be caused by the fact that the Bradford reagent has already been too long in the cuvette.
Tip: Use glass cuvettes for the Bradford method.

The Thermal Printer is delivered equipped with an appropriate cable. Replacement cables are available from us upon request.

Please send your Secondary UV-VIS-Filter set to your local Eppendorf partner.

We recommend checking the photometric systematic error (photometric trueness) and the wavelength systematic error (wavelength trueness) once a year using the Secondary UV-VIS-Filter set.

That depends upon the cuvette chosen. We recommend using the UVette with a minimum volume of 50 µl.

The BioPhotometer should not be used to measure an absorbance of less than 0.05 at 260 nm. This OD value corresponds to a RNA concentration of app. 2 µg/ml (= app. 100 ng RNA in 50 µl preparation). Please note that you should measure at 260 nm for a minimum absorbance of 0.1 in order to obtain exact results. This value is independent of the measuring device and is based upon the disturbing influence of impurities and particles on the measurement result, which is especially high at A < 0.1.

Factor F is calculated from the molar absorbance coefficient of a molecule in solution and the optical path length of the cuvette used (see Beer-Lambert law). The absorption behavior of nucleic acids is influenced by the aromatic rings of the bases. Here the molar absorbance coefficient of a double-stranded nucleic acid molecule with which the bases are in close contact with each other, is smaller than of a single-stranded nucleic acid molecule. It thus follows that single-stranded nucleic acid molecules have a higher rate of absorption than double-stranded molecules (Sambrook et al. 2001. Molecular Cloning 3rd edition, A8.20). With an optical path length of 10 mm and under neutral to slightly alkaline measuring conditions an optical density of 1 at 260 nm thus corresponds to approx. 50 µg/ml of double-stranded DNA, 37 µg/ml of single-stranded DNA, 40 µg/ml of RNA and appr. 30 µg/ml of oligonucleotides.

As of software version 1.20 you can easily and comfortably transfer measurement data into a table calculation program such as Excel using our BioPhotometer software package. The PC online program also enables the use of the familiar printout design from the thermoprinter with a PC printer.

It is 2 m long.

Yes.

This is caused by the measurement outside of the upper measuring range (> 3.0 A).
Please check
1. Whether your cuvette is pressed firmly onto the base of the cuvette shaft. The error message "++++" indicates that the cuvette base is blocking the light beam.
2. Whether your cuvette has an optical window at 8.5 mm.
3. Whether you have sufficient blank medium in the cuvette.

Due to the modularization of purity grades, some products are labeled with more than one purity grade symbol. For example, the epDualfilter T.I.P.S. has the double seal "PCR clean "+ "Sterile" and the UVette the double seal "PCR clean" + "Protein-free" on the packing. The certification remains unaffected by the modularization.

The previous purity grades were developed due to customer requirements and new applications, in the course of the years. To meet the customer requirements for single applications even better, Eppendorf has extended the certification of the purity grades "Sterile" (now, also certified as free of pyrogenes) and "Biopur" (now, also certified as free of DNase and PCR inhibitors). In addition, the previous purity grades have been transferred to a new modular system that provides the same variety and flexibility and yet is readily understandable.

For all purity grades, there will be new packing seals. In addition, there will be a further certification for the purity grades "Sterile" and "Biopur". "Sterile" will certify sterility and also the freedom of pyrogenes. The purity grade "Biopur" also includes the freedom of DNase as well as of PCR inhibitors.

The UVette is made of a UV-transparent plastic.

In general, the absorbance should be within the linear measuring range of the spectrophotometer (measuring range of Biophotometer: A = 0–3.0). For samples with a normal or a low concentration, the 10-mm light path is more suitable. For high-concentration samples (with A > 2.5), we recommend using the 2-mm light path. (An absorbance > 2.5 correlates to > 125 µg/ml dsDNA and > 100 µg/ml RNA respectively.)

The UVette can in principle be used in devices with which good results have already been attained using ultra micro cuvettes. To select the correct adapter, you need to know the light path height of your photometer. A summary of "UVette adapters" lists the relevant UVette adapters for numerous devices. If your device is not on the list, please ask the device manufacturer for the light path height of your device or contact our Application Hotline (Tel. +49 1803 666 789; support@eppendorf.com).

Please take a look into our brochure „Material resistance of the Uvette“, if your reagent is listed. You will find this brochure on our homepage. If your reagent is not mentioned, please ask our application-hotline for assistance (support@eppendorf.com)

Yes.

No. However, as with quartz glass cuvettes, it is important to make certain that the UVette is placed in the same direction in the cuvette shaft for both the blank and the sample measurement.

The light path height of a photometer informs you at what height, in relation to the bottom of a cuvette, the light beam of the photometer occurs.

All UVette adapters have dimensions of 12.5 x 12.5 mm. These correspond to the standard dimensions for cuvettes with 1 cm optical path length.

Up to 2,000 µl may be pipetted into the UVette.

Yes. Each UVette is packaged in such a way that the cuvette opening points toward the tear-strip of the blister-pack. In this way you can be sure not to touch the optical window of the UVette when tearing open the blister-pack.

You can do this by first measuring the sample, then rinsing the UVette thoroughly with buffer before measuring the blank. You must then subtract the blank value from your sample result.

With the Assay 490 method cytotoxicity assays can be evaluated with the BioPhotometer plus via endpoint detection. This assay is applied for testing the vitality of living cells. The assay is based on a lactate dehydrogenase reaction combined with a specific catalyst whereas the endproduct “formazan” can be detected at 490 nm in the BioPhotometer plus. Like in the method “Assay 340” the evaluation of the results could be done via a factor,a standard or a standard curve.

With the BioPhotometer plus 32 methods (23 programmed and 9 freely programmable methods) can be used. In the precursor BioPhotometer only 9 methods were available.

Yes, this is correct. Due to this change more applications are possible with the BioPhotometer plus, e.g., endpoint measurement of NADH based enzyme assays. The turbidity correction at DNA, RNA and protein measurements can also be carried out at 340 nm with the same sensitivity.

FOI means “Frequency of incorporation”, indicating the incorporation rate of dye–molecules into a biomolecule (e.g., molecules dye/kb DNA). This function will be available in the methods Dye550 and Dye650, respectively.

No. The unit for the dye concentration is defined permanently with "pmol/μl" and can therefore not be changed in the parameters.

This method is used for the evaluation of NADH based enzyme reactions. The enzymatic consumption will be analyzed via endpoint detection. NADH can be detected with the BioPhotometer plus at 340 nm. The evaluation of the results could be done via a factor, a standard or a standard curve.

With the optical pathlength of 0.2 mm microliter cell like the Hellma ®TrayCell (0.2 mm lid) can be used directly in the BioPhotometer plus without using any “virtual” dilution factors.

With the BioPhotometer plus the wavelengths 230 nm, 260 nm, 280 nm, 340 nm, 405 nm, 490 nm, 550 nm, 595 nm and 650 nm are available. With the “absorbance” key, all wavelengths can be used for direct measurement without using any calculation factors. The data can be used for further processing.

No, it is not possible to run kinetics in the BioPhotometer plus. However, due to the availability of the additional wavelengths many enzymatic assays can be carried out via endpoint detection.

Yes, in the method group “Routine” are all methods that also can be found in the BioPhotometer plus. These methods are the detection of nucleic acids, proteins, fluorescent dye labeled biomolecules plus OD600 measurements.

"Yes, this is possible. To consider the light path for the calculation of the sample concentration, this value has to be entered in the area “check parameters”. Please note, that for the use of the TrayCell a sufficient sample concentration has to be applied: For the available sample concentration we recommend the absorbance ranges (e.g. dsDNA): 0.1 mm = 500 – 5000 ng/µL 0:2 mm = 250 – 2500 ng/µL 1 mm = 50 – 500 ng/µL 2 mm = 10 – 100 ng/µL These concentration ranges for dsDNA correspond to an absorbance of 0.1 to 1 A. "

Basically every cuvette with standard dimensions can be used for the BioSpectrometer kinetic (s. chapter 5.2 in the manual). For optimal temperature control it is important that the cuvette has direct contact with the integrated peltier-element. Most adequate cuvettes are made of glass or quartz glass. In chapter 5.3.4 of the manual an overview is shown regarding pre-incubation times for different cuvette shapes.

In the method, "Advanced kinetics”, the measurement of standards can be programmed. This can be used for the measurement of unknown substrate concentrations via enzyme kinetics. Moreover it is possible if a drift of the reagent solution is expected, a “reagent blank” can be measurement. The result of this measurement is than subtracted from the sample measurement. These measurements are in the method "Simple Kinetics" not possible.

No, also this function is due to patent reasons not possible.

No, this is unfortunately not possible. But it is possible to export the data to an USB-Stick. The data can then be printed from the PC over a local or network printer.

For the BioSpectrometer an additional filter set will be available.

It depends, of course, on the usage of the Eppendorf µCuvette and the cuvettes shaft but a little bit play is actually normal. In any case the cuvette is automatically shifted to the correct position for the measurement.

Theoretically it is possible to measure up to 1500 µg/mL double-stranded DNA. This would be similar to an absorbance of 3, which is the maximum absorbance that can be measured in the Eppendorf BioPhotometer and BioSpectrometer. For optimal measuring results we recommend to use concentrations up 1000 µg/mL dsDNA (A=2).

For correct results the settings for the cuvette path length has to be changed to 1 mm in the parameter section: Select first the method family (e.g. DNA). Afterward go with the “cursor” key to your desired method. Press the “parameter” key move the cursor to the cuvette path length of 1 mm. For activating the new path length press the “enter” key. To leave the parameter section press “parameter” again.

Always use for cleaning lint-free tissue papers. Do not use any chemicals that are not recommended in the operation manual. Particularly substances that tend to corrosion such as acids or bases should be avoided.

It may be that not the right parameters are adjusted. Please check in the device if the programmed optical path length corresponds with the light path of the Eppendorf µCuvette.

Please check in the measuring results, e.g. if you want to determine the DNA concentration in your sample, if the purity ratios (260/280 or 260/230) are unusually high or low. Also a high background signal indicated by a high absorbance at 320 or 340 nm (A>0,1), can be a sign for a non-formed liquid-column. Please check also the scan result when using a BioSpectrometer for your measurement. If during DNA-measurements a typical absorbance curve is not displayed, the liquid column should be checked, too.

Alternatively you may program also a dilution. Programming a 1:10 dilution before the measurement will lead to the same result.

Since a 10 times smaller optical path length is used also the measured absorbance should be 10 times smaller. For this reason the result should be 0,12.

There is no specific direction recommended. The Eppendorf µCuvette has to be placed in cuvette shaft, that the optical window is aligned with the direction of the light beam of Bio- or BioSpectrometer. But it is necessary that blank and sample are measured in the same direction.

Yes, this is possible without any restrictions

This depends also to some extend to on the proteins. We recommend a volume of at least 3 µL.

The wavelengths 230, 260, 280, 320, 340, 405, 490, 562, 595 und 600 nm could be applied.

No, this is unfortunately not possible. But this is also not necessary since the results are exported directly as Excel-files. An additional program for data management is therefore not necessary.

This function is available for nucleic acid and protein detections.

No, unfortunately both options are not possible. This can be done only in the BioSpectrometer

Like for the BioSpectrometer the cuvette path lengths of 10, 5, 2, 1, 0.2, 0.1 mm could be programmed.

The data will be exported as Excel-files

This depends on the method. The free programmable methods offer 18 different kind of SI units. But it is possible at any time to edit new SI-Units?

The meaning of A0,1% is the absorbance of the Protein with a concentration of 1mg/ml.

About 1000 results can be stored in the BioPhotometer D30 or the BioSpectrometer.