EXPERIMENT 7

Question 1

Are dilutions made in “SERIES”

Answer 1

Serial Dilution

Question 2

In which the (?) is further diluted

Answer 2

original solution

Question 3

Here all dilution including or following the 1st one ARE

Answer 3

THE SAME

Question 4

General rule for calculating the concentration of solutions obtained by the dilution in series is to

Answer 4

multiply the original concentration by the first dilution

Question 5

Expressed as a fraction this by the (?) and so on until the desired concentration is known

Answer 5

second dilution

Question 6

Several laboratory procedures especially serologic methods make use of a (?) in which all dilutions including all following the first one, are the same.

Answer 6

dilution series

Question 7

Such dilutions are referred to as a serial dilution- a complete dilution series usually contains 5 or 10 tubes although any single dilution may be made directly from an (?)

Answer 7

undiluted specimen or substance

Question 8

Serial dilution is often used to measure the

Answer 8

titer of an Antibody

Question 9

Set of dilutions in which the (¿) is the same as each step

Answer 9

dilution factor

Question 10

These are used to make (?) with a small number of test tubes and minimal amount of (?)

Answer 10

high dilution

diluent

Question 11

Commonly done to determine the (?) of a particular antibody in a patient’s serum as a part of the diagnosis of a disease state

Answer 11

strength or titer

Question 12

is the reciprocal of the last tube in which a (+) reaction is seen

Answer 12

Titer

Question 13

The titer is written as the reciprocal of the dilution; that is the (?) is the last (+) one, the titer is written as (?)

Answer 13

1:60 tube

160

Question 14

When collecting a sample, spin the EDTA tube for (?) in the centrifuge at (?) and remove the plasma before adding the NSS

Answer 14

10 mins

1500 rpm

Question 15

Spin again for (?) and know the color of the saline wash on top and then wash (?) with NSS. Resuspend with additional saline uniformly. Repeat (?) or until the NSS supernatant is clear.

Answer 15

10 minutes

3x

3x

Question 16

To make a 4% RBC suspension add (?) NSS.

Answer 16

500 uL to 12 mL

Question 17

Note: when dispensing using a micropipette, it should be inclined and it should touch the side of the tube before dispensing, to improve accuracy of dispensing by (?) as compared to dispensing straight up.

Answer 17

1%

Question 18

Defined as the reciprocal of the highest dilution of the patient’s serum in which the antibody is still detectable

Answer 18

antibody titer

Question 19

Serial dilutions- perform continuous or series of dilution to a patient’s serum. Example, the original dilution of the tube is 1⁄2 followed by the next dilution 1⁄4, 1/8, 1/16 and 1/32. The antibody titer will be the last tube showing a reaction, either (?). Like in tube 4 there is still agglutination and then same as tube 1-3, but there is no agglutination in tube 5. The antibody titer is the 4th tube, a dilution factor of (?).

Answer 19

agglutination or hemolysis

16- antibody titer (1:16)

Question 20

When the concentration is too high or less specimen is available for analysis, the original specimen may be diluted or the initial dilution further diluted

Answer 20

Single dilution

Question 21

Dilute only once

Answer 21

Single dilution

Question 22

The reciprocal of the dilution is the dilution factor

Answer 22

Single dilution

Question 23

Method for determining of the concentration of substance. The greatest dilution of the sample that yields a positive result is the end point.

Answer 23

Serial dilution

Question 24

Used for determining antibody titer

Answer 24

Serial dilution

Question 25

Note: it also determines the strength of an antibody. The higher the titer, the stronger the antibody.

Answer 25

Serial dilution

Question 26

For most pathogenic infections, an increase in the patient’s titer of two doubling dilutions, or from a positive result of (?) over several weeks is an indication of (?). (?) increase from the original result after several weeks.

Answer 26

1:8 to a positive 1:32

current infection

Twofold