A photometric device (18) for quantifying a nucleic acid in a sample (518) in a tube (58), comprises a light emission unit (28), a sample obtaining unit (38) for holding the tube (58) with the nucleic acid sample (518) and a detection unit (48) wherein the sample obtaining unit (38) is arranged in between the light emission unit (28) and the detection unit (48) In particular, the light emission unit (28) and the detection unit (48) are arranged to provide light through the sample obtaining unit (38) such that light of a first wavelength of about 230 nanometers and light of a second wavelength of about 260 nanomaters are simultaneously detectable within the detection unit (48). The photometric device (18) allows for efficiently analysing the nucleic acid sample by only considering invisible light. In particular, content of nucleic acid such as particularly a RNA or a DNA and a nucleic acid/salt ratio can simultaneously be determined such that efficiency of quantification of the nucleic acid sample (518) can be increased. Furthermore, since in addition thereto the sample obtaining unit (38) is arranged to hold the tube (58) or cuvette and the light directly passes the sample (518) being arranged in the tube (58) or cuvette, loss of sample, contamination of sample, need of additional sample treatment equipment such as pipettes or additional tubes as well as frequent cleaning of optics of the photometric device can be prevented or reduced.