Saturday, March 5, 2011


As the pace of life Science Research and Development (R&D) accelerates, laboratories face heavy demands to produce timely accurate results as essentials requirement. The solution lies in the automation of laboratory instruments. About 30 years ago, hand held calculators began to find their way into the hands of college students and laboratory researchers. The more technically minded individuals promptly discarded their slide rules and turned to the new inventions that promised to process more and more complex data.
The era of the hand held calculator lasted about a decade. Then the desktop personal computer arrived and quickly overshadowed calculators. Since then, the computer industry has created a succession of smaller,faster, and smarter versions of the PC, with each new generation changing the lives of its users a little more. And just as the hand held calculator quickly found a place in the laboratory, personal computers in its various forms became an essential of bench research tool. Indeed, it has exerted a profound impact on the productivity of individual scientists and research terms.

It has certainly come to the aid of today's laboratory manager, who faces constant pressure to produce and deal with rapidly generated laboratory data. We are seeing a dramatic increase in the compound file. Whereas in the 1980s we were talking about tens of thousands of compounds in a library, now we're talking about millions. The increase in compounds to be screened and the resulting pressure on laboratory managers stem largely from three factors:
(i) The increased pace of R&D results and products new products;
(ii) The need for better quality control in industrial settings; and
(iii) Increasing cost control and government regulations in the clinical settings have combined to create numerical targets for screenings undreamt during the past decades.
Strategies for survival
To survive in the increasingly competitive environment, laboratories must produce results in a timely fashion with fewer errors and at lower cost. They must also find ways to utilize highly skilled laboratory personnel better by eliminating the redundant, low value tasks that they perform.

Automation offers a solution to many of these requirements. Its benefits include increased productivity via the ability to process larger numbers of samples per unit of time, a reduction in human errors caused by repetition and sheer boredom, and lower labor costs, which are a major component in testing procedures.
To cut the costs and improve the productivity of bench science, vendors of laboratory equipment are streamlining their instruments in several ways: e.g. well plates which used to have 96 wells at a time was increased to384 wells to cut the cost of reagents but now scientists face the prospect of using 1,536-well plates. With 1,536 wells an upward of half a million data points per day could be done, with a concomitant decrease in costs.

From Test Tubes to Plates
Most laboratories procedures can be broken down into three steps: sample preparation,sample analysis, and data management. Once computers arrived, the accuracy of testing and the ability to analyze complex sets of data soared. With data management dramatically improved, the work of preparing samples and running them through experimental protocols became the bottleneck in advancing productivity.In the 1980s the advent of automated systems brought together different hardware devices to accomplish specific laboratory tasks. Decreasing the time required for sample preparation was the next major step in improving laboratory productivity and quality.
The majority of the early progress in laboratory automation took place in the area of liquid handling. As sample volumes required for a reaction decreased from several milliliters to micro liters, experiments evolved from being conducted in test tubes to being performed in micro liter plates. The plates possessed several unique attributes that have made them the gold standard in handling many small volume samples. The precise predictable positioning of its wells permitted the use of multi-channel pipettes to dispense liquids into the plate. But while they offered a major improvement in productivity the plates didn't solve all the problems. Laboratory technicians continued to make mistakes and to forget which wells of a plate had received a chemical reagent. The procedure of pi petting into many rows of these 96-well micro liter plates was a tedious and boring job. Thus the next step in liquid handling involved the development and introduction of automated station to handle liquids. Originally considered luxury items, these instruments soon became common laboratory tools for researchers working with large numbers of samples.The stations allowed laboratory personnel to prepare micro liter plates with a limited amount of operator intervention and greatly improved accuracy. However, the instruments still needed to be hand fed with empty plates, and the filled plates needed to be removed, also by hand in most cases.
Today, several companies, including Packard,Robbins Scientific,and zymark offer automated liquid handling systems with software to program the steps involved in adding reagents to each plate. Technologists enter filling instructions into the instruments, often using user-friendly windows-based software programs.These programs also allow the process to be monitored and documented for auditing purposes.
Eppendorf is taking the process a stage further.They are working on an enzyme dispenser that will have the same handling characteristics that people are familiar with in their everyday micro liter pipettes, in addition it will accommodate small cartridges that can contain restriction enzymes or a very expensive, invaluable, or just isolated protein. It can then dispense the liquid in volumes between 10 nanoliters and one micro liter with high precision.

Speeding Up Screening
During the past ten years, combinatorial chemistry and high through put screening have profoundly influenced researchers' ability to produce and evaluate a group of chemical compounds for any number of purposes.This technology helped to decrease the time and amount of material needed to produce and screen many chemical compounds.Combinatorial chemists can produce a large number of compounds with varying but related structures, which can then be screened for biological activity. The pharmaceutical industry benefits most obviously from combinatorial chemistry. In the past, a medicinal chemist working for a pharmaceutical company might have been able to produce several new synthetic compounds each week.Today this same chemist using combinatorial chemistry techniques produces hundreds of related chemical compounds in a single day. Pharmaceutical companies are now building vast libraries of chemical compounds numbering in the hundreds of thousands and larger.High through put screening operations are analyzing up to hundreds of thousands of samples in a single day. This creates a need to process more compounds than ever before.
The micro liter plates that handle these compounds have already changed from 96-well to384-well versions. Recently ultrahigh through put screening (UTHS) instruments have started to reach the laboratory. Based on a 1,536-well micro liter plate format, these instruments possess robust liquid handling, specimen reading and data analysis capabilities. The UHTS instruments permit researchers to process over 100,000 samples per day.They use sample volumes of as little as 5 to 10 micro liters rather than the 100 micro liter required for conventional HTS. That means smaller amounts of reagents, a factor that can encourage scientists to screen more expensive or more precious substances.

Inside Live Cells
In addition to assaying minuscule volumes of compounds, researchers want to examine events inside cells as they occur. The technology for doing so has improved since the early 1970s when Becton Dickinson introduced the first commercial flow cytometer, the FACS-1. A few years later Ortho diagnostics followed suit with its version of this powerful cell analysis instrument. The flow cytometer enabled researchers to characterize populations of cells based on inherent cellular properties or fluorescent labels used to tag certain markers in or on the surface of specific cells. Coulter Electronics then introduced a flow cytometer multi parameter sorting capability. These instruments quickly became more smarter, allowing researchers to measure more parameters in a single experimental run. By the mid -1990s flow cytometer had advanced from sorting several thousand cells each second to cover 50,000 cells per second.
New Technologies to Read Plates
The success of live cell analysis techniques depends in large part on the ability to read accurately multi well plates, and particularly the 1,536-well versions. Imaging technologies are being used in this respect. The technologies are moving to cameras,charge- coupled device (CCD) chips , and laser based microscopy. Because it is laser scanning there is no wash involved, Assays to be done on particles and cells,and the only method of doing high-throughput apoptosis assays.

Molecular devices has improved  fluometric imaging plate reader (FLIPR), the kinetic imaging plate reader introduced in 1997 that allowed live cell assays to be used in primary screening. Chemistry has now been introduced to enable a very rapid no-wash procedure. Oldfield company now plans to expand the (FLIPR) technology. They have live ware products with chimeric G-proteins that allows screening for receptors that would normally be signaling through cyclic AMP. (CAMP adenoside 3':5' monophosphate). Another series of instruments from molecular devises, Chemiluminescence Plate Reader(CLIPR), relies on Chemiluminescence rather than fluorescence. It uses a very sensitive CCD camera that gives very flat field imaging, developed by Oldfield company. The lensing system from Affimax permits you to see everything on the plate without distortion.
From Automation to Robotics
Automation system are usually a combination of hardware devices interfaced together to perform specific laboratory procedures,such as filling micro liter  plates with a  substrate or other reagent. These can be very simple, dedicated workstations that perform a task or a group of tasks such as sample dilution,filtration, or the addition of reagent. The functions are fixed and often specific to a particular task or experiment.
In contrast, laboratory robotics system can usually perform many functions and can be designed and programmed to meet specific laboratory needs. They enable computers to do physical work in addition to processing data.These systems are very flexible in that they can be redesigned and reprogrammed to meet the changing needs of a laboratory environment.
Automation and robotics in laboratory instruments will continue to evolve in response to the  needs of customers. The tools will become even faster,smaller, and smarter, enabling researchers to gain new insights into the process of laboratory analysis. You can only improve as a laboratory technologist if you equip yourself to master the automation and robotics in laboratory instruments, because the industries, and R and D cannot stop their efforts to look for cheaper, faster and more reliable methods of analysis. However, if you
 stand still, two years from now, you will be far behind.
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Friday, February 4, 2011


INTRODUCTION:  Commercially produced chemical reagents such as acids and ammonia are highly <A HREF="">
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In order to prepare solutions of lower concentrations for titration, and for qualitative analysis, a calculated volume of the concentrated solution is taken from the stock solution and then added to a specified volume of distilled water. However the volume of such a solution to be taken depends on the information provided by the manufacturer on the label pasted on the stock bottle. For instance; the label on the stock bottle of concentrated H2SO4.


(a)                The specific gravity of 1.80 means that the stock solution is 1.80 times heavier than an equal volume of water; i.e. 1cm3 of the stock acid solution weighs 1.80g or 1000cm3 (1dm3) of stock solution weighs 1.80 x 1000 = 1800g.

(b)        The 98% by mass means: 98g of the acid (solute) is in 100g of solution i.e. 100g of stock solution contains 98g of H2SO4. 1800g (mass of 1dm3 of solution) contains (98/100) * 1800= 1764g. i.e 1dm3 of stock solution contains 1764g of pure H2SO4, therefore its mass concentration = 1764g/dm3. Hence, its molar concentration, C= 1764 per dm3/98g per mole  = 18.0mole per dm3
I.e. the concentration of the stock solution is 18.0 molar H2SO4

General formula: How to calculate molar concentration.
Generally, the original molar concentration, Co of a chemical substance of molar mass, M grams per mole in a commercial product of P% by mass and of density (or specific gravity) d gram per cm3 is given as Co = (10 * P * d)/M   or  Co = 10Pd/M
Where Co = Molar concentration of stock reagent
            P = Percentage purity (% purity)
            d = density or specific gravity
            M = Molar mass

Example:   Calculate the molar concentration of commercial trioxonitrate (V) acid of specific gravity 1.42 and 70.0% of acid (HNO3 = 63.0)
Co = ?  P% = 70, d = 1.42, m = 63
Co = 10Pd = 10 * 70 * 1.42 =15.8mole per dm3
           M                63
General formula:  How to calculate volume of solution to be diluted.
Take H2SO4 for example; prepare 500ml of 0.1m of H2SO4 from concentrated H2SO4 Specific gravity = 1.82, % purity = 97%, molar mass = 98
To know the concentration:
Molarity = 10 * P * d = 10 * 1.82 * 97 =18.01M
                         M                 98
Then, the amount of H2SO4 required to prepare 0.1M H2SO4 in 500ml can be expressed as follows:
C1V1  = C2V2
Where C1 = original concentration; V1 = volume required from the original solution.
C2 = concentration required, V2 = volume of new concentration required.
C1 = 18.01m,  V1 =?,    C2 = 0.1m,  V2 = 500ml
                           C1      18.01
Therefore, 2.78ml of concentrated H2SO4 will be required to prepare 0.1m of H2SO4 in 500ml.


97 or 98

Side-Bench Reagents
The following is a list of reagents required to carry out chemical analysis, and which should be readily available in reagent bottles on the side-bench in the laboratory. The directions for preparing the solutions are given.

Note: When diluting any concentrated acid, always add Acid to Water – never add water to acid.

Dilute HCl, 2 molar: Add 200cm3 of concentrated acid to 800cm3 of water.

Dilute HNO3, 2 molar: Add 125cm3 of concentrated acid to 875cm3 of water.

Dilute H2SO4, 1 molar: Add 55cm3 of the concentrated acid to 500cm3 of water, make up to 1dm3 with distilled water.

Dilute Ethanoic (acetic) acid, 2 molar: Dilute 114cm3 glacial acids with water to 1dm3.
Ammonia solution, 2molar: 153cm3 commercial product per dm3
Sodium Hydroxide, 2molar: Dissolve 80g of pellets (or solids) in distilled water and make up to 1dm3 with distilled water. Store in a reagent bottle with plastic stopper.
Ammonium trioxocarbonate (IV) (NH4)2CO3, 2 molar: Dissolve 160g of commercial solid in a mixture of 200cm3 of conc. Ammonia solution and 800cm3 of water.

Ammonium ethanedioate (oxalate): Make a saturated solution, filter, and use the filtrate.

Barium chloride, 0.5molar: Dissolve 122g of solid in 1dm3 of water.

Bromine water: Add 5cm3 of bromine to every 100cm3 of water shake well and store in amber coloured bottle.

Bromine in tetra chloromethane (carbon tetrachloride), CCl: Add 5cm3 of bromine to every 1000cm3 of CCl4 solution. Shake well to dissolve, store in amber coloured (dark) bottle.

Calcium chloride, 0.5molar: Dissolve 55g of solid in water and make up to 1dm3.

2, 4-dinitrophenylhydrazine: Dissolve 2.0g of the solid in 10cm3 of concentrated H2SO4. Add this solution to 200cm3 of absolute ethanol, dilute to 500cm3 with water, thoroughly, allow to stand, then filter and use the filterate.

Fehling’s solution A: Dissolve 35g of hydrated CuSO4 in water, add few drops of concentrated H2SO4 and dilute to 500cm3 with water.

Fehling’s solution B: Dissolve 60g of pure NaOH and 173g of Rochette salt (sodium potassium tartar ate) in 500cm3 of water, filter if necessary.
Mix equal volumes of Fehling’s solutions A and B just before use.

Hydrogen peroxide: 20-volume commercial product; or dilute 200cm3 of 100-volume commercial product with water and make up to 1dm3. Store in a dark bottle.

Lead ethanoate (acetate), 0.5molar: Dissolve 95g of solid in 500cm3 of water. Shake with about 5g of calcium hydroxide in 1dm3 water. Allow to stand for a few hours. Filter and use the filter ate.

Iron (III) chloride: Dissolve 67g of the crystals in 200cm3 of water.
Mercury (II) chloride, 0.25molar: Dissolve 7.0g of solid in 500cm3 of water
Methyl orange indicator: Dissolve 1.0g of solid in 1.5dm3 of boiling water.

Methyl red indicator: Dissolve 1.0g of solid in 600cm3 of ethanol, and dilute to 1dm3 with water.

Phenolphthalein indicator: Dissolve 1.0g of the solid in 500cm3 of ethanol and 50cm3 with water.

Potassium heptaoxodichromate (VI) (K2Cr2O7): Dissolve 1g of K2Cr2O7 in a mixture of 200cm3 of water and 40cm3 of 1mol/dm3 H2SO4.

Potassium tetraoxomanganate (VII) KMnO4(aq): Dissolve 1.5g of KMnO4 in a mixture of 400cm3 of water and100cm3 of 1mol/dm3 H2SO4. Store in amber coloured bottle.

Potassium hexacyanoferrate(II), 0.25molar: Dissolve 105g of solid in 1dm3 of water.

Potassium iodide, 0.5molar: Dissolve 83g of solid in 1dm3 of water.

Silver trioxonitrate (V), 0.1molar: Dissolve 17g of solid in 1dm3 of water. Store in amber coloured (dark) bottle.

Sodium trioxocarbonate(IV), 1.0molar: Dissolve 53g of solid in 500cm3 of water.

Sodium hydrogen tetraoxophosphate(V), 1.0molar: Dissolve 60g in 500cm3 of water.

Starch solution: Make a paste with 1.0g of soluble starch in a small amount of water and add about 100cm3 of boiling water. Boil the mixture for a while to obtain a clear solution. Prepare when ready to use.

Tin(II) chloride, 1.0molar: Dissolve 56g of solid crystals in 500cm3 of 1.0molar HCl solution. To prevent oxidation, add a few pieces of tin metal.

Barium trioxonitrate(V), 0.5mol/dm3: Dissolve 130g of solid in 1000cm3 of water.

Lime water (Ca(OH)2(aq): Dissolve 25g of Ca(OH)2 in 1dm3 of distilled water, shake, stir and then keep with tight cover for a day, decant the clear and colourless solution later filter and later keep the filtrate in a corked reagent bottle.

Iodine solution: Dissolve 120g of solid iodine in 1000dm3 of distilled water to which 3.5g KI have been dissolved before.

Disodium trioxosulphate(II) (Na2S2O3.5H2O), 1mol/dm3:  Dissolve 248g of solid in 1dm3 of distilled water.

Preparation of Reagents in %w/w, %w/v and %v/v

Preparation of reagent in %w/w: It means a particular weight of a solute in 100g of solution. For example 98%w/w H2SO4 means: 98g of the acid (solute) is in 100g of solution, i.e. 100g of stock solution contains 98g of H2SO4.

Preparation of reagent in %w/v: It means a particular weight of a solute in 100cm3 of solution. For example, 20%w/vNa2CO3 means: 20g of Na2CO3 in 100cm3 of solution.

Preparation of reagent in %v/v: It means a particular volume of a solute in 100cm3 of solution. For example, 10%v/v acetone means: 10cm3 of acetone in 100cm3 of solution.

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