Lab Machines

what is it

diopter adjustment

what is it

nose piece

what is it

mechanical stage

what is it

condenser

what is it

illumination

what is it

brightness adjustment

what is it

base

what is it

light switch

what is it

fine adjustment

what is it

coarse adjustment

what is it

stage control

what is it

frame (arm)

what is it

objective lens

what is it

head

what is it

ocular lens (eyepiece)

define Mechanical stage

The platform on which the slide or object is placed for viewing.

define stage bracket

hold the slide or specimen in place on the stage.

define stage control knobs

These knobs move the slide or specimen either horizontally (x axis) or vertically (y axis) when it is being viewed.

purpose of arm/frame

Used to carry the microscope.

what are the binocular microscope adjustments

1. Interpupillary distance

2. Individual ocular adjustment

Individual ocular adjustment is aka

diopter adjustment

define Interpupillary distance adjustment

adjusts distance between oculars so that you see a single field.

purpose of Individual ocular adjustment

compensates for any differences between your eyes

functions of ocular eyepieces

1. Magnifies the real image formed by the objective.

2. Forms a virtual image of the real image.

3. Can carry measuring scales for micrometry to measure the specimen

why is measuring important in micrometry

some species are similar so measuring identifies them

define rotating nosepiece

The rotating nosepiece holds objective lenses and allows for quick exchange of objectives.

Most compound microscopes have what 4 objectives

1. 4X

2. 10X

3. 40X

4. 100X.

microscope objectives are the first to

produce a real image

define magnification power

the degree to which the visual of an object has been altered.

4X is for

scanning/park position

10X means

low dry objective

40X means

high dry objective

100X means

oil immersion objective

Higher power objectives are — — for safety

spring loaded

how to calculate magnification

Take the power of the objective (4X, 10X, 40X) and multiply by the power of the eyepiece, usually 10X.

when measuring under 10x multiply by

10

when measuring under 40X multiply

2.5

when measuring under 100X multiply

nothing, it’s already at the actual size

why is oil required on 100X

Oil is required so that the light rays are not refracted when they pass from the slide to air before entering the objective lens.

define condenser

Is a series of lenses mounted in such a way that the object and the slide are completely and evenly illuminated.

define iris disphragm

this controls the amount of light coming up into your scope.

define field diaphragm

controls only the width of the bundle of light rays reaching the condenser.

define illuminator

Built-in low voltage illuminator on the underside of the microscope. Illuminating apparatus is a built-in light source.

define Kohler Illumination

a method of adjusting a microscope in order to provide optimal illumination by focusing the light on the specimen

How to Set up Kohler Microscope Illumination (5)

1. The Condenser should be all the way up to the stage (unless looking at urine or feces)

2. Your Iris Diaphragm lever (under the stage) should always be at 70-80% open so light can enter the condenser.

3. Light intensity should be between 3-5.

4. The Field Diaphragm should be between the “ C and the “L” , not to the open position.

5. Make sure that under 10X, your field of view is centered. And if not please do so by using the Centering Screws

define micrometry

The science of measuring objects under the microscope

oculars can be cleaned with (2)

dampened soft cloth or lens paper

how to store microscope (9)

1. Turn off light

2. Lower stage completely

3. Ensure the 4X objective is in place (lowest objective)

4. Condenser down

5. Remove slide

6. Oculars together

7. Replace dust cover

8. in cupboard; place arm out

9. power cord neatly around base

how to carry microscope

one on the arm and one under the base

what happens if you don’t carry a microscope properlly

ocular can fall out

what to do when No light when you switch to oil immersion lens

check to see that you have placed a drop of oil on the slide.

what to do when viewing is blurry or unable to focus under 40x (2)

1. can mean your slide is upside down

2. you could have accidentally dipped it in oil causing blurry vision.

what to do when unable to see anything under urine or fecal sample,

your light is too bright - lower condenser

what happened when you cracked your slide under 40x or 100x,

you used the course adjustment knob

define centrifuge (2)

1. A centrifuge is designed to accelerate sedimentation by taking advantage of centrifugal force.

2. It is used to separate substances of different densities in a solution.

define Microhematocrit centrifuge (3)

1. This centrifuge is used exclusively for spinning down microhematocrit tubes

2. This process is used for determining a patient’s packed cell volume (PCV)

3. can also provide a plasma sample for protein analysis.

what are the 3 main types of clinical centrifuge (3)

1. variable-angle centrifuges / horizontal centrifuge

2. define fixed-angle centrifuges

3. multi-use centrifuge

define variable-angle centrifuges / horizontal centrifuge

The tube or bottle is held in a shield or cup, which is attached to the head so that it is free to swing from a vertical position (at rest), to a horizontal position when the centrifuge revolves.

define fixed-angle centrifuges

The fixed-angle centrifuge has buckets that are in a fixed position, typically about 50°.

define Multi-use Centrifuge (2)

1. Many centrifuges are multi-use, able to accommodate urine, blood, and hematocrit tubes.

2. These centrifuges have specific centrifugal force settings for each specific type of sample and feature removable shields

Relative centrifugal force (RCF) assumes (2) …

1. a unit mass

2. uses the force of gravity as a base unit.

what does RCF stand for

Relative centrifugal force

function of RCF

It is a function of the speed of rotation and the radius from the centre of rotation to the point at which the force is to be determined.

what units are RCF in (unit + unit name)

g - gravities

safety precautions of microscope (5)

1. Check electrical specifications of instrument before plugging in.

2. Be sure the centrifuge is balanced to avoid excessive vibration, which results from improper balancing.

3. Never, under any circumstances, open the lid of the centrifuge while the motor is running.

4. Never stop a centrifuge with your hands. There is a danger of catching hands in revolving parts, remixing of sediment, and causing excessive wear on the machine.

5. If there is glass breakage inside the centrifuge, do not open the centrifuge for 15 minutes to avoid aerosols. If any glass is broken remove the head and clean the bowl thoroughly.

define refractometer

measures the refractive index of a solution and is an indirect measure of the specific gravity.

how do refractometers work (2)

1. When a solution (e.g., urine) is measured, light passes through the sample and bends.

2. The angle of this refraction is visualized as a shadow and correlates with the concentration of the solution.

what do refractometers measure (2)

1. blood total protein

2. urine specific gravity

how to calibrate refractometers

take a reading with distilled water that should be 1.000

use a small screwdriver to turn the zero adjustment setting clockwise to — reading

increase

use a small screwdriver to turn the zero adjustment setting counter clockwise to — reading

decrease

MCHT Procedure (7)

1. make your 2 microhematocrit tube with required whole blood

2. spin it in the centrifuge.

3. Now carefully remove it from the centrifuge, and break it in half appropriately (just above the buffy coat)

4. Now carefully place the protein (unbroken side of MHCT) just overtop of the refractometer prism (rectangular glass section)

5. And place a small amount of the protein plasma onto it. You may need to gently jar the tube in a forward motion to get the substance out. (note - stay very close to prism but not close enough to touch it)

6. With the cover plate depressed, gently press it down to hold/ spread the plasma protein as you lift the refractometer up towards the light and look through the eyepiece to view scale.

7. Using the SP (serum protein) scale, the reading scale is taken at the boundary line separating the light and dark area.

8. Rinse prism and cover plate with distilled water between samples and dry with Kimwipe.

Urine SG procedure (4)

1. put a small drop of urine (spun or unspun) onto the refractometer with a pipette

2. With the cover plate depressed, gently press it down to hold/ spread the urine as you lift the refractometer up towards the light and look through the eyepiece to view scale.

3. Using the S.G (specific gravity) scale, the reading scale is taken at the boundary line separating the light and dark area.

4. Rinse prism and cover plate with distilled water between samples and dry with Kimwipe.

define incubator

provides the ability to artificially control the environmental temperature (and humidity, to some extent) for many microbiological procedures.

define Coagulation analyzers (2ish)

1. prothrombin time (PT)

2. activated partial thromboplastin time (aPTT)

3. fibrinogen tests can be performed using fresh or citrated whole blood.

what is IDEXX ProCyte for

CBC

what does IDEXX ProCyte give for results (6)

1. Detection of band neutrophils

2. Reticulocyte count

3. Reticulocyte hemoglobin (RETIC-HGB)

4. True five-part white blood cell differential

5. Detection of nucleated red blood cells

6. The ability to run abdominal/thoracic, synovial fluid analyses

define Laser flow cytometry

delivers an advanced five-part white blood cell differential.

define Optical fluorescence

provides a highly sensitive and accurate reticulocyte count.

define laminar flow impedance

performs the fastest, most precise red blood cell count

Laser Based / Impedance Technology princple

Laser beams determine the density of solid components and their size.

Color Photometry Principle (2)

1. The photometer receives whatever light is not absorbed by the sample.

2. A signal is then transmitted to the readout device as a unit of measurement.

what additive in in red/gold/tiger cap (3ish)

1. serum

2. with or without clot activator

3. with or without gel

what additive in in green cap (4ish)

1. sodium or lithium heparin

2. with or without gel

what additive in in lavendar/pink cap (2)

1. potassium

2. EDTA

what additive in in gray cap (3ish)

1. sodium fluoride

2. sodium or potassium oxalate

what function is the additive in blue cap

prevents blood from clotting by binding calcium

what function is the additive in red/gold/tiger cap

1. clot activator promotes blood clotting with glass or silica particles

2. gel seperates serum from cells

what function is the additive in green cap

prevents clotting by inhibiting thrombin and thromboplastin

what function is the additive in lavendar/pink cap

prevents clotting by binding calcium

what function is the additive in gray cap (2)

1. fluoride inhibits glycolysis, and oxalate

2. prevents clotting by precipitating calcium

common lab tests for blue caps

coagulation

common lab tests for red/gold/tiger caps (3)

1. chemistry

2. serology

3. immunology

common lab tests for green caps (2)

1. stat

2. routine chemistry

common lab tests for grey caps (3)

1. glucose

2. blood alcohol

3. lactic acid

common lab tests for lavender/pink caps (2)

1. hematology

2. blood bank

what is blood

the body’s fluid connective tissue

what is plasma

is the bloods liquid component

what does blood contain (4)

1. RBC

2. WBC

3. Platlets

4. Plasma

what does Plasma contain (8)

1. water

2. proteins

3. waste products

4. minerals

5. clotting factors

6. immunoglobins

7. carbon dioxide

8. hormones