Objective of the Experiment

Lactate dehydrogenase (LDH) is an oxidoreductase that catalyzes the conversion of lactate to pyruvate. It consists of four subunits that may be of two different types M and H ( muscle and heart formerly known as A and B, respectively). Five different isoenzymes are therefore possible, depending on the subunit composition  

LDH-1 and LDH-2 are predominant in the heart, while LDH-4 and LDH-5 predominate in skeletal muscle and liver. The molecular weight of all isoenzymes is 140 kDa. 

L(+)-Lactate dehydrogenase is specific for l(+)-lactate and does not react with d(—)-lactate. LDH is used in coupled enzyme assays, for example in the determination of ATPase (Penefsky and Bruist 1984), myokinase (Brolin 1983), and pyruvate kinase (Beutler 1971). It may also be used in the determination of lactate (Noll 1984), pyruvate (Lamprecht and Heinz 1984), and various other metabolites. 

Students should follow reaction number 1 here. They should follow the disappearance kinetics of NADH with absorption spectrophotometry. 

Before entering the laboratory, students should be able to explain a kinetic reaction and to demonstrate how to calculate reaction kinetic constants. 

---

Transient Studies in an Adiabatic Packed-Bed Reactor was the title of a publication by Berty et al (1972). This was in connection with thermal runaway of reactors. The pertinent subject will be discussed in a following chapter in which the interest is focused on how to avoid the onset of a runaway. Here the object of the experiment was to see what happens after a runaway has started. 

The experimentation in the field of gas cloud fires appears to be limited. The unique set of large-scale experiments that involve the release, dispersion, ignition, and combustion of flammable natural gas clouds in the open air is that with the code name Coyote. Coyote series trials conducted by LLNL in 1983 at California s Nevada Test Site, Nevada provided an integrated dataset for use in validation studies [64,65]. The objective of the experiments was to determine the transport and dispersion of vapors from LNG spills, and in addition to investigate the damage potential of vapor cloud fires. Transient simulations... 

A new HP-TLC method has been applied for the quantitative analysis of flavonoids in Passiflora coerulea L. The objective of the experiments was the separation and identification of the compound(s) responsible for the anxiolytic effect of the plant. Samples were extracted with 60 per cent ethanol or refluxed three times with aqueous methanol, and the supernatants were employed for HPTLC analysis. Separation was performed on a silica layer prewashed with methanol and pretreated with 0.1 M K2HP04, the optimal mobile phase composition being ethyl acetate-formic acid-water (9 1 l,v/v). It was established that the best extraction efficacy can be achieved with 60 - 80 per cent aqueous methanol. The HPTLC technique separates 10 different flavonoids, which can be used for the authenticity test of this medicinal plant [121],... 

It should be noted that although it has been stated that the environmental variables are beyond the control of the manufacturer in the normal production or usage conditions, it is necessary that they can be controlled for an experiment. The objective of the experiment is to learn how to minimize the influence of the environmental variables on the product or process performance. To accomplish this objective it will be necessary to understand how variation in environmental conditions affects the product or process performance. The methodology that will be described in this chapter requires that the environmental conditions be changed in a controlled, structured manner. 

The choice of whether to make the mean the primary or the secondary response will depend on the objectives of the experiment. For example, if the objective is to have the mean on target with minimum variation then the dual response approach would suggest minimizing the variance (or... 

Figure 9.3 is a sketch of an apparatus that can be used to determine the equilibrium extent of gas adsorption as a function of pressure. We outline how such an experiment is conducted at ambient temperature, even though adsorption studies are frequently conducted at low temperatures, particularly when determination of Asp is the objective of the experiment. A known mass of adsorbent is introduced into the sample tube and degassed as described above. Then the following set of pressure-volume readings are made, described here in terms of Figure 9.3. 

Experimental Design. The first objective of the experiment was to determine which of the five factors listed above were of decisive importance, and to quantify their effects and their eventual interactions. The number of variables (k = 5) being limited, a screening was not required, and a 2k factorial design was chosen [130,136]. In this type of design, all experiments are performed with variables set at two different levels, which correspond to the limits of the experimental region and which are coded (-1) and ( +1) (coded variables are denoted Xf) (Table 2). 

The objective of the experiment is to evaluate the action of restriction enzymes on bacterial plasmids, A phage DNA, or viral DNA. The DNA will be incubated under the appropriate conditions with selected restriction enzymes. The reaction mixtures will be subjected to agarose gel electrophoresis in order to determine the number and molecular size of the restriction fragments. 

Sample dilution. The solution used to dilute the sample needs to be carefully considered in terms of the objectives of the experiment. Remember that the sample itself will contribute some salt and will be at a particular pH. 

Reduction with hydrogen is a preliminary step in practically all of the experiments dealing with chemisorption on metals. In most cases the sample is cooled to 35° C. in an atmosphere of hydrogen. Usually an attempt is made to observe a band due to chemisorbed hydrogen even though this may not be related to the major objective of the experiment. Despite many such attempts with a wide variety of samples, no band has been observed which could be attributed to chemisorbed hydrogen. 

The specific objectives of the experiment were to determine critical concentrations of Pt necessary for stable passivity of the surface alloy in IN H2SO4 and to aid understanding of the mechanisms of noble metal redistribution. 

NEXAFS experiments on NOM can be conducted in several modes that differ in the type of detected particle and objectives of the experiment transmission (X rays transmitted through the sample), fluorescence (fluorescent X rays due to absorption of the X-ray beam), or electron yield (photo-emitted electron) (Sparks, 2003). Alternatively, the techniques can be divided into full-field applications such as transmission X-ray microscopy (TXM) and X-ray photoemission electron microscopy (PEEM), in comparison to scanning techniques such as scanning transmission X-ray microscopy (STXM) and scanning photoemission microscopy (SPEM) that provide spatial information of elemental forms. 

KAERI is joining the PYCASSO experiment to investigate coating behaviour under irradiation (Groot, 2008). The objective of the experiment for KAERI is to analyse the porosity and property changes of a pyrolytic carbon buffer layer as a function of neutron fluence and temperature. Approximately 10 000 coated particles of four different coating layer densities were provided for PYCASSO. 

Sixty compounds were tested for their ability to induce reciprocal translocations in male germ cells 26 were classified as positive, 8 as negative, and 26 as inconclusively tested. There were 76 compounds reported in tests for chromosomal breakage involving partial chromosome loss 27 were classified as positive, 13 as negative, and 36 as inconclusive. Many of these studies involved less sensitive test systems than are now available and were done at a time when screening was not the objective of the experiment. 

The objective of the experiments is to compare the affinity of wild-type antibody and wild-type immunogen (chicken lysozyme) with that of wild-type antibody and mutant antigen or with that of mutant antibody and wild-type immunogen. All the assays involve incubation of a constant concentration of one reactant with varying amounts of the complementary reactant, along with estimating the concentration of either bound or free reactant by an immunochemical or enzymatic method. In each case, the assumption is made that the measurement step does not disturb the equilibrium between antigen and antibody, and it is important that this assumption be validated experimentally. We summarize below several alternative methods. 

Several criteria for design selection have been proposed in the literature. The choice of criterion depends on the objective of the experiment. Here, criteria for model estimation capacity and model discrimination capability are described. 

The object of the experiment described below is to set up a gas thermometer, calibrate it at the ice point (in lieu of the experimentally more difficult triple point), and use it to determine the temperatures of one or more other fixed points. These may include the steam point, the boiling point of liquid nitrogen, the sublimation temperature of solid carbon dioxide (Dry Ice), the transition temperature of sodium sulfate decahydrate to the monohydrate and saturated solution, etc. The experiment will be performed with an apparatus that... 

---