I had a problem opening the document loaded into the ROI. Here it is: 

Development of a small scale rumen in vitro incubation system for high-throughput screening of methane inhibitors
Stefan MUETZEL, Sarah LEWIS, Ron RONIMUS and Michael TAVENDALE1 
Animal Nutrition & Health, AgResearch Ltd., Palmerston North 4402, NZ

One advantage of rumen in vitro systems is their high sample throughput compared to studies in vivo. However, when screening several thousand compounds is required, even the highest throughput systems available have limitations. As part of a large research program to determine the efficacy of potential methanogen inhibitors, we developed a small scale (200 µl) in vitro incubation system suitable to analyse up to 200 incubation vials in a day.
The samples and substrates are incubated in 1.2 ml glass vials in a 96-well format, flushed with carbon dioxide. Incubation is carried out for 4 to 6 h at 39°C. The plate is then transferred to a GC (Shimadzu GC2010 plus) fitted with a Restek MXT-PLOT column and a pulsed discharge ionization detector. The samples are injected directly from the incubation vials into the inlet with a split ratio of 20 and analysed as a single run at 85 °C isocratic with a column flow of 4.76ml/min. The proportion of methane and hydrogen is determined from the response of a standard gas and estimates of the gas production are obtained by analysing the dilution of the nitrogen peak compared to the blank incubation where no substrate is added to the rumen fluid. The results from these incubations are variable, but the system can detect full or partial methane inhibition, total gas production and the occurrence of a hydrogen peak indicative of a methanogen inhibitor. Furthermore, the system can differentiate between true methanogen inhibitors and alternative hydrogen sinks and is a new tool for high throughput screening of large compound libraries in rumen fluid. 
