Cd and Pb tissue concentrations

What may sound like a very simple question is driving crazy 2 experienced lab technicians. We run growth inhibition tests with green algae using 5 ml incubation volume and low algal density. At the end of the incubation, the incubation media has to be removed from the samples and algal cells are analyzed for various biochemical markers. Intuitively, centrifugation seems to be the method of choice, however, algae vary a lot between the controls and toxic treatment in their ability to sediment at 16 g, no matter how long we spin them. This is clearly depending on the biochemical composition of the algae (amount of sugars produced?), but this is what makes it absolutely crucial to get a similar sedimentation efficiency in treatments and controls.

Filtration on GFF is not an option, because at the end the pellet has to be resuspended in a very low volume of liquid, which will be impossible with the filter.

We have been struggling with this forever...

do someone hava a bacterial culture of Chromobacterium violaceum?

interesting interdisciplinary papers:

Chatzinikolaou Y. , Lazaridou M. Identification of the self-purification stretches of the Pinios River, Central Greece. — Mediterranean Marine Science, 2007, Volume 8/2, p.19-32.

Brooks, B.W., Riley, T.M., Taylor, R.D. Water quality of effluent-dominated ecosystems: Ecotoxicological, hydrological, and management considerations. - Hydrobiologia, 2006, 556 (1), pp. 365-379.

Fisenko A. I. A new long-term on site clean-up approach applied to non-point sources of pollution // Water, Air, & Soil Pollution. 2004, Vol. 156, No. 1-4, p. 1-27.

Fauvet, G., Claret, C., Marmonier, P. Influence of benthic and interstitial processes on nutrient changes along a regulated reach of a large river (Rhône River, France). -Hydrobiologia 2001, 445, pp. 121-131.

Hernandez, I., Fernandez-Engo, M.A., Perez-Llorens, J.L., Vergara, J.J. Integrated outdoor culture of two estuarine macroalgae as biofilters for dissolved nutrients from Sparus aurata waste waters. – 2005, Journal of Applied Phycology, 17 (6), pp. 557-567.

Jiang, J.-G., Shen, Y.-F. Estimation of the natural purification rate of a eutrophic lake after pollutant removal, 2006, Ecological Engineering, 28 (2), pp. 166-173.

When we use metal compounds like Copper sulfate, Copper chloride, Lead chloride... how can we attribute the toxicity to the metal species alone? I guess it is not enough if we just make the concentration based on the metal special alone...

We cannot avoid the effects of the compounds like sulfate or chloride.. how can this be addressed?

Please give me your suggestions.

Toxicity of cephalexin on acethylcholinesterase activity, Gluthathione-s-transferase, lipid peroxidation and EROD activity. Also, toxicology on laboratory animals, fish etc.

In Algae due to heavy metal Toxicity.