How to use a microscope and oil immersion

Summary

El guion ofrece una lección detallada sobre el uso de un microscopio para la microbiología, enfocándose en técnicas específicas como la inmersión en aceite. Se anticipa la frustración de los estudiantes al usar esta técnica por primera vez y se enfatiza la importancia de encontrar bacterias con el objetivo de 100x. Se sugiere seguir ciertos pasos para asegurar una buena observación, como centrar la muestra, ajustar el condensador y limpiar el microscopio adecuadamente tras su uso. La lección también resalta la necesidad de paciencia y práctica para identificar correctamente a las bacterias.

Takeaways

• 🔬 El script trata sobre el uso de un microscopio para la microbiología, con énfasis en la observación de bacterias con técnicas de tinción.
• 👀 Se asume que los estudiantes tienen conocimientos previos sobre el uso de un microscopio, pero se centrará en detalles específicos para la microbiología.
• 📚 Se enfatiza la importancia de comprender cómo usar un microscopio antes de la clase, especialmente para evitar perder tiempo ajustándolo durante el laboratorio.
• 💡 Se menciona la necesidad de ajustar la luz y el condensador para obtener una buena iluminación y enfoque al observar las muestras microbiológicas.
• 🔍 Se recomienda comenzar con la lente de 10x para encontrar la muestra antes de aumentar la magnificación a 40x o 100x.
• 🚫 Se advierte que nunca se debe usar aceite para la inmersión en lentes de 4x o 10x, ya que esto dañaría el microscopio.
• 🛠️ Se describe un truco para ajustar el condensador, asegurándose de que está en la posición correcta para un enfoque óptimo.
• 📉 Se sugiere que si se tiene dificultades para enfocar, volver a la lente de 10x y reajustar puede ser útil antes de intentar con lentes de mayor magnificación.
• 🌟 Se resalta la importancia de la paciencia y la persistencia al usar la inmersión con aceite, especialmente para distinguir colores y detalles en las tinciones.
• 💧 Se explica cómo aplicar y limpiar el aceite de la lente de 100x, enfatizando la delicadeza y el uso de papel de lente para evitar daños.
• 🗑️ Se da instrucciones sobre cómo almacenar y mantener el microscopio después de su uso, incluyendo la limpieza y el cuidado adecuado del equipo.

Q & A

¿Qué se espera que los estudiantes hagan con las manchas que han creado?

Los estudiantes deben observar las manchas bajo el microscopio para estudiar las muestras de orina y microbiología.

¿Por qué el instructor no cubre los detalles básicos del uso del microscopio?

El instructor asume que los estudiantes ya tienen conocimientos previos sobre el uso de un microscopio y se enfoca en el uso del microscopio para la microbiología.

¿Qué herramienta se menciona como nueva para todos y que requiere atención especial?

La inmersión con aceite (oil immersion) es una herramienta nueva para todos y requiere que los estudiantes comprendan cómo usarla correctamente.

¿Por qué es importante no pasar mucho tiempo buscando una mancha durante la clase?

El tiempo en el laboratorio es limitado y es necesario enfocarse en encontrar las bacterias lo más rápido posible, manteniendo la precisión en el proceso.

¿Qué se debe hacer si se siente frustrado al intentar usar la inmersión con aceite?

Es normal sentirse frustrado al principio, pero se debe persistir y seguir intentándolo, ya que es una habilidad requerida para la clase.

¿Qué indica el instructor sobre la importancia de la posición del condensador en el microscopio?

El condensador debe estar en la posición correcta para evitar problemas de enfoque, y el instructor sugiere un truco para ajustarlo correctamente.

¿Cuál es el primer objetivo al usar el microscopio para encontrar organismos?

El primer objetivo es encontrar la muestra con el objetivo de 10 veces antes de proceder a aumentos mayores.

¿Qué sucede si se coloca la muestra en el microscopio al revés?

Si la muestra se coloca al revés, se pueden tener problemas para enfocar en los objetivos de 40 y 100, por lo que es importante verificar la orientación de la muestra.

¿Por qué es obligatorio usar la inmersión con aceite con el objetivo de 100 veces?

La inmersión con aceite disminuye la refracción de la luz, proporcionando una muestra nítida y con el color correcto, especialmente para las técnicas de tinción como la Gram.

¿Cómo se debe limpiar el lente de 100 veces después de usar la inmersión con aceite?

Se debe usar papel de lente para limpiar el lente de 100 veces, y se debe hacer con delicadeza, sin usar ningún otro tipo de paño o líquido.

¿Cómo se debe almacenar el microscopio al final de la clase?

El microscopio debe ser apilado con el objetivo de menor potencia hacia abajo, el escenario debe ser bajado completamente, el brazo debe estar centrado y el cable debe envolverse en la parte posterior del microscopio antes de colocarlo en su lugar con número correspondiente.

Outlines

00:00

🔬 Uso avanzado de microscopios en microbiología

El primer párrafo aborda el uso de microscopios para la microbiología, enfocándose en técnicas específicas y no en los aspectos básicos de su manejo. Se espera que los estudiantes ya sean familiarizados con su uso, pero se resalta la importancia de la atención al detalle y la práctica para aquellos que no lo son. Se menciona la necesidad de utilizar el inmersión en aceite para observar bacterias, una técnica que puede ser frustrante al principio pero es esencial para ver bacterias con claridad y color correcto. Se da un consejo sobre cómo alinear el condensador para mejorar el enfoque y se enfatiza la importancia de encontrar la bacteria con el objetivo de inmersión en aceite antes de abandonar el aula.

05:00

📚 Detalles técnicos de preparación y observación de muestras microbiológicas

El segundo párrafo se centra en los desafíos técnicos de manipular y observar muestras microbiológicas. Se discute cómo colocar las muestras correctamente en el microscopio para evitar problemas de enfoque, especialmente al utilizar el objetivo de 100x con inmersión en aceite. Se explica que el uso de aceite es obligatorio para obtener una imagen nítida y color correcto, y se proporciona una guía paso a paso para aplicar el aceite y enfocar la muestra. Además, se sugiere cómo solucionar problemas de enfoque y se enfatiza la necesidad de volver a empezar si no se logra un enfoque adecuado tras aplicar el aceite.

10:01

🖌️ Identificación y registro de bacterias con microscopio

El tercer párrafo se centra en la identificación y el registro detallado de bacterias a través del microscopio. Se enfatiza la importancia de encontrar bacterias específicas en lugar de simplemente 'blobs' grandes, y se motiva a los estudiantes a perseverar en la búsqueda de bacterias incluso si es difícil. Se da una descripción de cómo limpiar el lente de 100x después de usar aceite, y se ofrecen consejos para mantener el microscopio y las muestras en buen estado al final de la sesión de laboratorio.

Keywords

💡Microscopio

El microscopio es un instrumento óptico utilizado para observar objetos que son demasiado pequeños para ser vistos a simple vista, como las bacterias. En el video, se menciona que los estudiantes ya tienen experiencia usando un microscopio, por lo que no se revisarán los detalles básicos de su uso. Se enfoca en el uso del microscopio específicamente para microbiología, subrayando la importancia de la precisión en la observación de bacterias bajo diferentes niveles de aumento.

💡Inmersión en aceite

La inmersión en aceite es una técnica avanzada utilizada en microscopía para mejorar la resolución y claridad de la imagen cuando se utilizan lentes de aumento alto, como el objetivo de 100x. El aceite reduce la refracción de la luz y permite una mejor visualización de las bacterias. En el video, se enfatiza que los estudiantes deben usar esta técnica para obtener una imagen clara y precisa de las bacterias antes de poder abandonar la clase.

💡Bacterias

Las bacterias son organismos microscópicos que a menudo se estudian en microbiología. En el video, se menciona que las bacterias son muy pequeñas y, por lo tanto, no se pueden ver a simple vista. Los estudiantes deben usar la técnica de tinción y el microscopio para localizarlas, y se les recuerda que es fundamental que puedan encontrarlas correctamente durante la práctica de laboratorio.

💡Tinción

La tinción es un proceso utilizado en microbiología para resaltar y hacer visibles las bacterias bajo el microscopio. En el video, se hace referencia a que los estudiantes han realizado tinciones y que estas son esenciales para identificar las bacterias durante la observación. Además, se explica que las manchas pueden no ser visibles a simple vista, lo que hace que el uso correcto del microscopio sea crucial.

💡Lente de 100x

El lente de 100x es una lente de alta potencia en un microscopio que, junto con la técnica de inmersión en aceite, permite la visualización detallada de microorganismos pequeños, como bacterias. En el video, se explica que este es el único lente que debe usarse con aceite y que los estudiantes deben ser extremadamente cuidadosos al usarlo para evitar daños al microscopio.

💡Condensador

El condensador es una parte del microscopio que concentra la luz sobre la muestra para mejorar la claridad de la imagen. En el video, se menciona un truco para ajustar el condensador, asegurando una mejor visualización de la muestra. Si el condensador no está en la posición correcta, puede haber problemas de enfoque.

💡Enfoque fino

El enfoque fino es un ajuste en el microscopio que permite afinar la claridad de la imagen cuando se utilizan lentes de mayor aumento, como los de 40x o 100x. En el video, se enfatiza que una vez que se encuentra la muestra con el lente de 10x, los estudiantes deben usar el enfoque fino para afinar la imagen a medida que pasan a mayores aumentos.

💡Lente de 40x

El lente de 40x es una lente de potencia intermedia utilizada en microscopía antes de pasar al lente de 100x. En el video, se recomienda a los estudiantes usar el lente de 40x después de encontrar la muestra con el lente de 10x. También se advierte que este lente no debe entrar en contacto con el aceite de inmersión, ya que puede dañarse.

💡Diagrama de diafragma

El diafragma es un componente del microscopio que controla la cantidad de luz que pasa a través de la muestra. En el video, se menciona que el diafragma debe ajustarse para reducir la intensidad de la luz cuando se observan bacterias a bajo aumento. Esto ayuda a mejorar la visibilidad y reduce el deslumbramiento.

💡Limpieza del microscopio

La limpieza del microscopio es un paso crucial después de su uso, especialmente después de emplear inmersión en aceite. En el video, se da una explicación detallada sobre cómo limpiar el objetivo de 100x usando papel especial para lentes, advirtiendo a los estudiantes que no deben frotar con fuerza ni usar otros materiales de limpieza que puedan dañar el equipo.

Highlights

Instructor expects students to have prior knowledge of using a microscope and focuses on microbiology-specific techniques.

Students are reminded to be familiar with microscope operation to save class time for bacteria identification.

The importance of oil immersion technique is emphasized, as it is crucial for observing bacteria clearly.

Students are warned not to give up when using oil immersion, even if it is frustrating at first.

The instructor details the process of preparing the microscope, including adjusting the light source and condenser.

A trick for checking condenser placement is shared, using a loop for focus before specimen observation.

The necessity to start with the 10x power objective to locate the bacteria before moving to higher magnifications is explained.

Parfocality of microscopes is mentioned, ensuring students that adjusting to higher powers won't displace the specimen.

The instructor advises on proper focusing techniques, including focusing away from oneself for clarity.

A common mistake of placing the slide upside down is pointed out, which can cause focusing issues.

The requirement of using oil immersion for the 100x objective to accurately identify bacteria by color is discussed.

Instructions are given on how to apply oil to the slide without contaminating other lenses.

The process of focusing under oil immersion is detailed, emphasizing the need for precision and patience.

The instructor provides troubleshooting tips for when the specimen is not visible or in focus.

A step-by-step guide on cleaning the 100x lens after oil immersion with lens paper is described.

The importance of not rushing the process and accurately identifying bacteria is stressed for successful staining and observation.

Students are advised on how to store and handle the microscope properly after use, including turning it off and wrapping the cord.

A final reminder to carry the microscope with care, especially noting the heat from the light source.

Transcripts

okay now that you've made your stains

we're going to look at them under the

microscope I am expecting the urine

microbiology and you have the

prerequisites and you have used a

microscope before so I am NOT going to

go over the nitty-gritty details of how

to use a microscope I am going to focus

on using a microscope for microbiology

if it has been a while since you've used

a microscope or you've never used one

you will need to play close attention to

the details and make sure that you know

what you're doing when you come to class

I'm not going to be able to spend a lot

of time with students showing them how

to use a microscope oil immersion I will

help you out with because it's something

new to all of us so make sure that you

understand what you need to do with the

microscope how to use it before coming

to class you don't want to spend an hour

trying to find a stain we have limited

time and we need to focus on finding

these bacteria as quickly as we can not

saying that you should be so fast that

you don't do it right the other thing is

we're going to use oil immersion and

with oil immersion students get a very

very frustrated and don't be alarmed if

you get frustrated and can't do it the

first time you will be required to do it

so just say don't say I can't do it and

I'm looking to my students my partner's

microscope that's not going to happen

you will be required to use oil

immersion you must use oil immersion for

these stains and you must find the

bacteria with the oil immersion lens

before you can you leave the classroom

now as we get started let's think a

little bit back about what we've done so

we've made some stains and remember that

I had to draw circles to where you're

going to put your stain where you're

going to put your smear that was to make

sure that when you look under the

microscope you're looking in the right

place when you look at this you may feel

like there's nothing on this light

looking at it with the naked eye

remember bacteria are so small you may

not see your smear with the naked eye so

drawing that circle was so that at least

when you put it on the microscope you

have somewhere to shoot for it so when

we put on the microscope you put it in

that clip you put it over the light

source so it's for

not centered you're going to move it

over the light source one of the other

things that I notice right away is this

might the light is really bright under

the low powers I'm going to want to turn

it down so I'm going to use the

diaphragm lever and I'm going to close

it a little bit by moving it to the

right to kind of cut down on the white

the other thing that you want to look at

is right here is the condenser sometimes

the condenser is way down here and you

will have focusing issues if you don't

have it in the right place so you're

going to want to put it to where it's

pretty close to the slide right below it

okay now we are dealing with bacteria

that are very very very small so we do

not need to worry about the 4x power

we're just going to skip that we're

always going to start with the 10 okay

you will have to find the organism find

the smear with the 10 power before you

go any further okay now to see if your

condenser is in the right place I have a

little trick so what you do is you find

your specimen by using the coarse

adjustment knob with the temper I kind

of found it there now to see if your

condenser is the right place take your

loop hold your loop over the light

source looking through the microscope

try to focus on the loop it'll be a

little bit blurry

so what you can do is you move the

condenser until your loop comes into

focus your specimen will go out of focus

once that's done that's exactly the

perfect place for your condenser so if

you do that at the beginning of a lab

before you do any microscope work you're

going to have better focusing it's a

little little trick that I learned it

takes just a minute if you skip it you

might have issues with focusing okay so

now I'm going to refocus by using my

fine adjustment knob on my specimen so

now I found it with the 10 power ok now

I'm going to go to the 40 notice that I

do not move the slide you may go oh it's

going to hit it's not going to hit okay

if you're in focus these are parfocal

microscopes it's not going to hit so now

that I'm on the 40 I am NOT going to use

the course

adjustment knob I can only use the fine

adjustment knob so my kind of rule of

thumb is in most cases if you focus away

from yourself it will come into focus if

it doesn't try the other direction if

you feel like you're just focusing

focusing focusing focusing and focusing

take a step back go back to the tan

readjust some things that can happen is

you may not have it centered okay

make sure that you're centered right in

the middle of the specimen okay so now

I'm going to go back to the 40 oh I see

it it's a little bit blurry but I see it

so I'm going to focus okay going away to

work so I'm going to come forward so it

just depends on the specimen one of the

things that can occur is when you're

making those slides it's going to be a

little bit cumbersome and you have a lot

of different slides that you're working

with what can happen is students get a

little bit out of sorts I guess is the

word and they put their slide on upside

down okay you will have focusing issues

on the forty or the 100 if your slide is

upside down so if you can never focus on

the 40 go back to the tan lower to the

stage take the slide off and see if it's

upside down okay

now I'm focused on the 40 I can now go

to the 100 now I don't go directly to

the 100 you must must use oil immersion

it is not an option you may say well I

can see it under the 100 which may be

true you'll see something blurry two

things will occur either it will be the

wrong color or it will always be out of

focus you must use the oil immersion to

decrease the refraction of light so that

you get a clear visible specimen and it

is the right color when we do the Gram

stain you're distinguishing between pink

and purple

it may be pink without the oil purple

with the oil the correct answer is

purple so you have to use the oil

immersion to use the oil immersion I

don't want to get any oil on this lens

the only lens that can ever have oil on

it is

hundred let me repeat that the only lens

that can ever have oil on it is the 100

getting oil on the 40 of the 10 is very

very bad it will permanently damage the

microscope so I do not want to put the

oil on yet but I do not want to go to

the hundred so what I'm going to do is

see how I'm turning it to where I have

this specimen between the 40 and the 100

now I'm going to take oil it may be in a

bottle like this it may be in a bottle

like this doesn't matter if I use this I

have like a little medicine dropper

thing and you let the oil drop off okay

if you use this it's a dropper bottle

and you just squeeze a drop off doesn't

matter which one you use

you put the smallest drop of oil you

possibly can do not touch the slide with

the actual bottle or the dropper okay

only if you let the oil touch the slide

it'll pull it off the dropper now that I

have the oil on there now I want to take

a step back do you notice I did not move

the stage I did not move the slide if

you are focused with the 40 it will work

with the 100 make sure that it is apples

absolute focus and it is centered on the

slide before you put the oil on it's

kind of like the point of no return

so then I clip the 100 into place so now

I see it it's a little bit blurry fine

focus so I find focus and it cut she

comes right in now once again if you

find that your focusing the heck out of

it you have an issue your slides upside

down your condensers in the wrong place

it may be that your microscope is dirty

we deal with those kinds of issues now

if you're focusing the heck out of it do

not use the coarse adjustment to focus

okay if you're having issues what should

you do last time I told you to go back a

step I told you to go from the 40 to the

10 you cannot go from the 100 to the 40

because you will get oil on the 40 lens

we cannot have

oil on the 40 lens if you get to this

point and you cannot find it you must go

back to the ten to focus now you're in a

situation where you can find it under

the ten but you cannot go to the 40 so

you have to go focus go back to the 100

do not go through the 40 and focus again

this will be a little bit harder so

remember make sure your specimen is

perfectly focused on the 40 before you

use oil immersion if this doesn't work

going back to the 10 you're going to

have to start over

which means you lower put it on a

low-power

lower the stage clean the oil off the

slide by dabbing it with a chem wipe and

then you'll have to start over you

cannot ever go to the 40 if there is oil

on your slide so once again focus focus

focus on the 40 before you use the oil

so now you've done all the right things

you have it under the hundred it's good

and focused you can find it it's really

important that you don't give up on this

okay you need to make sure that you can

find the correct specimen you're going

to see a lot of stuff on there you may

see big blobs of stain one of the rules

to keep in mind is bacteria is very very

very tiny if you have a sale what looks

like a sale that's taking over the whole

field of view you are not looking at

bacteria it's a blob of something small

bacteria so don't be drawing things that

are big blobs that's the wrong thing

that's what I'll be able to tell from

your drawings you must find the bacteria

because everything you do after this

will be the same in terms of staining

and finding specimens if you can't find

them on the first day work work work at

finding them because the next day you're

not gonna be able to find them the next

day you're not going to be able to find

them and you're going to be frustrated

through half of the semester so do not

skip this and say oh I can't find it

under the oil I'm not going to do it you

must do it

okay so now I'm done I found my

specimens I've done my drawing I'm done

with the slide okay so what you're going

to do so remember it was way up there on

the hundred you're going to go to a

lower power lower the stage remove your

slide now we need to get the oil off of

the one hundred lens to get the oil off

the one hundred lens you use lens paper

don't use any other kind of paper don't

use a paper towel don't use a chem wipe

it must be the lens paper and I do not

want you to rub it off and I want you to

be very gentle okay so you just take the

paper and you dab and dab and you go to

a dry spot and you keep dabbing until no

oil comes off do you see how I'm just

gently dabbing I'm not pushing really

hard and I'm not rubbing I don't know if

you can notice but there's where the oil

started and as I dabbed it got less and

less and less so if you dab and nothing

comes off that means you're done don't

use a liquid to clean it off or anything

now you're done looking at your specimen

make sure that you keep your slides for

just a minute

talk to your lab partners before you

throw them out because you don't want

you know if they're stained in one work

they can use yours okay

so keep them for a minute talk to your

lab partners before you especially if

you have a really good one you want to

share it with the class

okay now that I'm done I want to put my

microscope away correctly so now I'm

going to take it always turn it to where

the lowest power is facing down you're

going to turn off your microscope lower

the stage completely you're going to

Center the little arm and you're done so

now you unplug it wrap the cord around

the back I don't need to do for it

you're going to put the cover on it and

remember when you take it back to the

microscope cabinet you carry with both

hands one hand will be holding the arm

the other hand will be underneath the

base keep in mind the base gets really

hot because of the light so when you put

your hand

they're just it's going to be hot but

you still have to hold the microscope

okay when you put it into cap in the

cabinet the lens side goes in first the

whatever this thing is called the cord

will be facing you always put it back in

the spot with the number that is the

same number as the number on your

microscope